Does anyone think system requirements given on PC games are specious?

I have bought PC games that should have been able to play on my computer. They start out like they might play, then they start lugging down and become choppy and unplayable. I am not talking about just having minimum system requirements either. My computer meets the "required" system stats for a game, and still I have trouble. I am mainly referring to ram, processor, and video card requirements. And yes, I have Direct X 9, a decent sound card, and enough hard drive space. Going to lower resolution and reducing requirements about detail and shadowing, etc. seems to provide only a temporary fix, if any (I do like a good graphics, and avoid stuff like that if I can). I am beginning to think that the little joking remark I heard on X-Play once is about right : That you need a NASA super computer and the sacrificial blood of a virgin to even get computer games to play these days. Any suggestions (aside from "get a console"), comments?