If you are seriously under the impression that Ray Allen isn't a top 10 shooter in the league, I doubt it'd be worth arguing over. Seems like you're pretty set in your (false) criteria, and I don't think anyone will be able to change your mind.
But his career average and his season average is not great at all.
I'm happy to change my opinion if you can give me definitive proof that Ray Allen is a top 5 ot 10 shooter in the league, other than when he hits his one out of every three 3pt attempts, you think to yourself.... "thats automatic" and "that looks sweet".
Ray's overall shooting percentages fall because he shoots a lot more three's than anyone else. This past year he shot 8 3's a game. Last year it was almost 9. His 3-pt percentage is actually quite good (high 30's, not low 30's like you're suggesting), especially considering the shot selection.
Watch Ray Allen play, see the degree of difficulty on shots he takes compared to, say, Kyle Korver, and get back to me with that "argument" that only FG%/3P% matters. Name a guard that's a first option on his team that you think is a better shooter than Ray Allen, and explain why.