I disagree with your definition of criticism, Darkstar, and I also disagree that you cannot criticise something you could not do better yourself. A dictionary says this about “criticise”:
To express one’s views as to the merit or demerit of; esp., to animadvert upon; to find fault with.
To discuss the merits or demerits of a thing or person; esp., to find fault
I criticise ZyX for making art where the characters are consistently too similar to each other, and not really all that pretty either. I don’t have to be able to do better myself to criticise ZyX, because I know it CAN be done better by others. “Better” is of course in the eye of the beholder here, as it’s a matter of individual taste.
I can criticise anyone who does a job inadequately, even if I cannot personally do better myself. If I am paying someone to fix my car, and my car is actually behaving worse afterwards, it is totally irrelevant that I couldn’t have fixed it by myself. I am paying, so I have every right to criticise the job that has been done when the NORM is far better than what I have gotten.
Not to mention the classic/cliche example of a doctor slipping up during surgery, then asing you if you could do better yourself. It’s not about if you can personally do better, it’s about if you should be able to EXPECT better.
Then again, this is about ZyX art. It’s not really a question of good or bad, but of taste. My main criticism is that nearly all the ZyX characters are too similar. And in that field, I actually CAN do better. I can draw characters that look more diverse than ZyX characters do. They might not have any artistic merit whatsoever beyond looking very different from each other, but at least I can beat ZyX at that.