Ask HN: Taking the Long View

I've been thinking a lot about the future and what type of nights-and-weekends project I want to work on next. Probably not the next project and probably not the one after that, but eventually I want to turn one of them into a company that I can work on full time. There's a lot of great guidance out there on how to come up with a killer business idea. YC's "Make something people want" stands out among them. By adhering to that maxim alone you could probably do very well, but I feel like its missing something. There recently was a discussion about a site called Parrot Secrets, which sells an eBook about raising and owning parrots. According to one site, the owner makes a few hundred thousand dollars a year from the site and he doesn't even own a parrot. He made something people want and has become very rich because of it. I don't want to start a site like that. "But why not?" I kept asking myself. Indeed, if the goal is to make money, there's a lot of easier ways to do it other than a Y Combinator-type startup. I realized that I very much want to build a long term company. Something that I can still be running 20-30 years from now. Not some fish-widget-flashy-url-shortener-social-network-thingy. My question boils down to this: How do you identify an idea that has the potential to become a long term business? I think the key is founding a company with a vision and not simply focusing on acquisition. Bonus question: How does YC feel about companies who say they are not interested in getting acquired?