"Shit" has always been a swear word. Would you let your toddler walk around saying "This is shit!" while pointing at random things in public? It'd be a funny online video, but I wouldn't want to be the parent in the video. Just because you casually say to your friends, "I gotta take a shit." Doesn't mean it's not a swear word in most cases. "Poop" isn't even close. That's a word we intentionally teach toddlers to say.

I'm actually curious. Would you be 100% ok with your (hypothetical) toddler doing that? If so, then you really don't see it as a swear word. I feel like the vast majority of people in the USA would say it's a swear word.

A swear word is just a "lowly" word with a bit more gravity than normal words. Consider how even "This is trash!" Doesn't carry the same weight as "This is shit!".

You can insult things and people with any words... "naive, ignorant, uneducated, slow, ineffective, disabled", etc. But if a person were actually any of those things, and you spoke those words with tact, they aren't necessarily mean. "I'm sorry to say this, but disabled people do not have a good time on this ride."

Now replace "disabled" with "shit" and tell me that could ever be gentle in any context. 😂 That's what makes it a swear word, that's it. It's a word that has no chance of being "nice" in any way.

These are just my own thoughts, and I'm certainly no linguist.