Isn't good dj'ing not just about being able to beat mix, or pull off tricks, but about your selection of tunes, how your set flows, noting how people respond on the dancefloor and reacting accordingly?

I think good dj'ing implies good tunes, or at least a good choice of tunes. The tunes on their own might not be up to much but a good dj can make it an important part of his set.

I hate hearing a dj mess up mix after mix in a club. Anyone can make a mistake, that's OK with me and I usually have a laugh when someone messes it up, but the flow of things is very important to me and you can't get a good flow when it's constantly interrupted by crap mixing.