When I visit a café, I intend to chill out a while, so I think I'm also paying for the atmosphere, seats, convenience etc. If you're just grabbing a cup on the way to work, you get exactly zero atmosphere, so why pay extra for it. Since that takes about as much time and effort as brewing your own coffee, the price difference is just crazy. Why pay more for a paper cup of mediocre dark roast, when you could pay less for a delightful cup of light roast with fruity flavors. The kind of specialty coffee I used to drink, each cup would cost about half of what you would pay at a café.

Once I learned what to look for in a cup of coffee, it ruined café experiences for me. They just don't have anything good. It's either medium roast or dark roast. Cafe latte still works, because it covers the bitter taste of dark roast espresso so well.