Why would I hate on Castle? I'm a spurs fan, I hope he'll do good. Do I believe he'll be a bonifide star? No, but I'll happily say I was wrong if he does. I'm only judging what I'm seeing hic et nunc, not fantisizing.
You want a more objective opinion? Read what other fanbases are saying. And guess what? There's barely any real chatter around Castle, or just to mention he can't shoot. No one is saying "Crap, we missed on Castle!". And there's barely any hawk fan regretting picking Risacher over him.