We are talking about the same thing. Kerning is a good thing, it increases readability. In a perfect world everything would be hand kerned for the best results

We are talking about the same thing. Kerning is a good thing, it increases readability. In a perfect world everything would be hand kerned for the best results, but that's not realistic. The compromise is automatic kerning, which isn't as good, but isn't too shabby. However, when you full justify text you're forcing the computer to abandon its best attempt at good kerning. Like newspaper on silly putty it gets stretched into spacings that aren't clean. Even if it leaves the spacings between letters untouched that forces it to make large and uneven spacings between words. Some people might prefer that, and some people might prefer copy set to look like random letters. It's hard to have generalized rules that fit everyone. In general though I think it the standard position taught typography is to not justify text except in special situation.