If I want to play a sniper, I'll play a sniper. If I want to play a deeps or def hero, I'll do so. Nobody can stop me from doing that.
If you want to stop that kind of behavior, then gather a ton of players and make blizzard add the same amount of competitive points to quick play.
That'll solve the whole issue, because most people are playing competitive for the points, so the golden weapons are technically the root of the problem.
Those guys don't care about rank.