Compression can be very useful, and in fact I incorporate compression often, both in the creation of my own recordings and the mastering of other people's recordings.
But the notion that compression automatically makes things sound "better" is nonsense. In many cases it can make things sound worse. It's nothing more than a tool to change the relative dynamics between loud and quiet parts in a given segment of audio. Used casually, compression is more likely to screw things up than improve things. I've screwed up a master more than once by getting too compression-happy, and ended up going back to pre-compression version of the master and trying to solve the level or volume issues again some other way.
I think there is no right or wrong, in the end...it all comes down to personal preference and taste... It all depends on context and how you use it, if we speak compression in an mastering or mixing context, it is completely different..
There is both good and bad things about compression, but one thing for certain is that it brings "clarity" into the mix, since you hear the whole dynamic range more clearly, but yet less dynamic... As I see it a lot of music today is totally destroyed in the mastering process, where they compress everything to the max to get the extra "boost" or "power". Metallica's "Death Magnetic" is a good example sounds like total crap.