Just because something is "advertising" or "social" does not mean that it is "completely trivial and useless". Very few big problems are solved in one fell swoop. Most of them are overcome by thousands of people chipping away at various parts of them at the same time.
You're right, they totally left out invasive, obnoxious and manipulative.
vs.
>Most are just doing some advertising, social nonsense, crappy games, or something else completely trivial and useless as a money-grab.
>But I would only make things I cared about, at my own pace, and for free.
vs.
>Also, anythign I did build would be something that would make the world a better place.
It's like you waver between taking a self serving "Take-the-money-and-run" attitude and complaints that others are in business solely for greed.
I don't know if I'm more blown away by that, or your cynicism toward startups. Ideas that are trivial and useless are not going to make money. However, ideas that YOU find trivial and useless could very well make money.
I think it's important to consider the viewpoints of others and perhaps while Farmville brings no joy to your life, it doesn't mean it can't be a fun and rewarding experience to someone else.
Also, anythign I did build would be something that would make the world a better place. Some startups do try to change the world for the better. Most are just doing some advertising, social nonsense, crappy games, or something else completely trivial and useless as a money-grab.