Edit: ITT: Lemmings in denile that their personal problems are mostly due to their lack of social skills, not capitalism.

Because being "a quiet person" almost universally indicates some kind of problem that is or is going to hold you back in life. It usually indicates that you have social anxiety, poorly developed social skills, have a negative outlook and disposition, have little confidence in yourself or your opinions, are just plain dumb or dull, some other weird thing, or some combination of the above.

Being "introverted" is a typical excuse quiet people use. But the actual definition of introversion just means you have a greater affinity for alone time - not that you rarely speak in social situations. Being quiet is corrolated with being introverted - if you have a larger affinity for alone time, you will likely practice socializing less frequently, leading to less confidence, leading to a greater aversion to social situations, which can become a viscuous cycle. But this is a skill issue, not an intrinsic character trait, and people with greater introversion can and do excell in any number of social situations all the time.

Meanwhile, being a "quiet person" will hamstring you in basically every aspect of life. Humans are social animals, and being able to socialize effectively is one of the biggest advantages you can have.

Want to get good grades in school? Well teachers are more willing to give you a break or extra help if they know you because you talk to them. Other classmates are more willing to form study groups with you. You'll have a better chance of forming a team with the smartest kids for class projects.

Want to excell in your career? It helps if you are a chatterbox who interviews well. It helps if you love meeting new people in your industry and form a big network of people who like you. It helps if you can have a fun conversation with your boss, or your boss's boss, or your boss's boss's boss's boss. So you really still believe, in this day and age, that if you quietly keep your head down and get your work done better than everyone else, that you will be first in line for raises and promotions? No! Your ability to perform useful tasks quickly means that you probably won't get fired - but mostly because it means that they expect that they'll be able to save on the budget, since you'll never have the courage to ask for anything more than an inflation raise. And being promoted is mostly about giving you authority over others - and who the fuck is going to respect the authority of someone who never speaks and can't hold anyone's eye contact?

Want to have friends? A large and diverse social group who can support you in times of need? Help you fix your car, give you a couch to crash on, give you career advice, invite you to join in fun new hobbies, give you a sense of warmth and community, and be your emotional support system when your whole life goes sideways? Well guess what? Most people only really care about someone else if they know that person, and the primary way you know a person is by listening to them talk about things. Sure, as a quiet person you will probably gain a small group of close friends who you actually can speak freely with - but someone who speaks freely with everyone will have 10x the social connections or more. A quiet and reserved person can lean on their circle of a half dozen friends in time of need. A social, charismatic person can get help from someone they met once, ten years ago, in a different country. And even if the quiet person truly loves their small circle of friends - life happens. People get busy with jobs, or kids. They move to different places. They change their priorities in life. People die. Friend circles which aren't consistently adding new members tend to dwindle over time, and you could very easily end up completely alone if you never developed the skill of meeting new people and developing relationships with them.

And dating? I don't care if you want a white picket fence and a golden retriever, or want to blow your load on a different pair of titties every night of the week - quiet people get fucked in dating. Wait. No. The opposite of that.... Yeah, they typically aren't getting fucked. At least not by the people they want. Forget about any talk of "game" or charisma - the biggest factor in dating success is literally just the number of attractive strangers you say "hi" to. If you have a hard time going up to a stranger and saying "hi", if you join a conversation by entering the circle and then never say a word, or if you rarely show up to social events where there are new people present, then your pool of potential dates will be extremely limited solely because you can't end up dating someone that you never say a word to. And beyond playing the numbers game - hey guys, what do women want? Everyone say it with me - CONFIDENCE. Okay, so how is any given woman going to know you are confident? Probably by the fact that you walk into a social situation smiling and eager to talk to people, because you are confident that people will like you, and you are confident that meeting new people will be fun. And girls - ya know when you see the guy who shows up to the party and everyone cheers when he walks in? The guy who has amazing hair and a hot body and who spends his weekends taking disadvantaged urban youth on backpacking trips? Sure, maybe he'll take a shine to you and have a fling, and maybe that will turn into something long term - but if he's looking for a girlie to be a long term partner, who is he getting obsessed with? Probably the girl who is dashing around the room squeeling with joy every time a new person arrives and giving them a huge hug, the girl who is excitedly talking about her hobbies, job, or emotional revelations to a circle of smiling friends and acquaintances, the girl who is grabbing people and dragging them onto the dance floor to get the party started. Sure, statistically everyone finds someone, eventually... but the people who are having a good time and getting compliments from their friends about their amazing new partner, are going to be the people who talk a lot to a lot of people.

This isn't to say that quiet people can't be happy, can't have friends or partners, or can't succeed in life. And maybe someone will say that this whole analysis is shallow and misguided, and that pursuing any of these things by opening their mouth and speaking more would be a betrayal of their deep inner self or something. But this is kind of like choosing to be homeless because getting any kind of job would be a betrayal of the cause of overthrowing the capitalists and creating a utopian society. Like, if you really feel that way, I guess I can't change your mind - but its not the life I would choose for myself, and I can understand why someone wouldn't want it for their child.