Nothing good about using more chords than you need. In fact I think it's best to use as few as you can.

If you need lots of chords in a song, use them. I've got one where I use, I think, 54 chords (some of them are inversions, all right), and that's for a particular reason. But most of the time three are fine, and sometimes less than that.

I can't see why anyone would wish to come across on the Cat as a bigger bastard than they probably really are in real life. As always the question arises, which is the real you, the one the world sees, or the one we see...

But as I said, I think a lot of this is we're thinking in terms of different types of settings, where different ways of reacting to a singer are maybe appropriate. People who are overconfident invite a more robust type of criticism than those who are underconfident. "That was pretty bad" (ie "that sucked") might be an appropriate thing to say to someone who you knew had it in them to do a lot better, and who knew that themselves. Basically, mostly it'd only be the right thing to say as a kind of backhanded compliment.