I would have to see a definition of "hack". The term is used so broadly it practically has no meaning.

Some people consider a hack to be anything that is not semantically correct. In which case almost everyone hacks because 100% semantic pages are very rare (I don't even code them that way myself all the time, unfortunately).

Other people only consider it a hack if you can't write one style that works in all browsers. Unfortunately again, it's almost impossible to code this way without violating the semantic hack definition due to the fact IE does not support all w3c standards.

The bottom line is, if your page works in IE then chances are you've hacked by some definition or another.