Isn't closed to your social circle? OP wants something that helps you expand to other social circles. Arrive to a new city none of your friends are in, and have an app tell you what is around you based on your interests and posts.
Yeah, true. OP expresses his concern over Facebook's ad revenue system, the clutter it creates and how it spoils his entire Social Network experience. Path, on the other hand gives a user a rich and a personal experience. I guess that's the trade-off there. For getting recommendations based on location and interests, I use Circle(discovercircle.com). Works fine for me. :-)
You just described the social network I'm working on now, and like a couple of other posters have mentioned, our entire userbase is teens and college aged people at the moment.