What is wrong with this site?
There is nothing wrong with this site. In fact, I am not far off from putting the actual 'CSS compliant' icons on here somewhere. Much more likely, you are using a browser that does not conform to Web Standards (tm).
I could say a lot of bad things about a certain monopolist company that has not only forced essentially crud software down the throats of 98% of the world's computer users, but has managed to dumb down expectations to its own level in the process. But I won't.
Instead, I urge you to have a read of one of the links and resources below. See whose opinion you trust or otherwise value. See the multitude of examples. If you can (not all of us are in the fortunate position to choose which software we use), try one of those other browsers. At worst, it might cost you some time and some bandwith. So does reading this site. In fact, that goes for almost the entire web. So what have you got to lose? You could gain a whole new level of enjoying the web. Many have before you.