The argument for Kane seems to be that "He's young", which is also the counter to all sceptics. The thing is that at least some of us who don't rate him are not just looking simply at the question "is he good enough at the moment?" We are trying to look at what he does, his skillset, and wether it's likely that he will become a player of the quality we hope Spurs will have in the years to come. To me, it seems he has to many weaknesses that won't develop far enough at this age.
I'm not one of those that hate on all players or all talents though. It's just - he doesn't look good enough, and also lacked focus in the last game. If you're young and want to make it, you should make damn sure to stay focused when you play.