I used to feel this way and eventually deleted my LinkedIn account. I eventually created another when we started fundraising and it's actually turned out to be a somewhat useful tool.

I completely ignore my timeline and I only connect with people I've met. LinkedIn's been helpful when I find a potential donor (or someone else I want to talk to) and I can see who's connected with them. If I have a 2nd degree connection with them, then I begin my research to actually see the best way to get in touch with them. Far too many people connect with people they don't know for LinkedIn alone to be a useful tool.