By no means am I saying the cavs playing zone would have resulted in them winning the series or anything like that. It was simply a suggestion as to how Blatt could hide Kevin if he were playing in the finals.
However, to say someone shouldn't play zone because a zone "invites shooting" is an extremely simplistic way of looking at defense. A Zone may invite shooting, but the warriors led the league in paint points. That in theory, would be cut out a bit with a zone. So yeah they'll be shooting and making perimeter shots, but no team succeeds with a diet full of jump shooting.
If for nothing else, it offers a different dynamic that offers more rest to counteract their lack of depth.