Definitely. Just because it's been going on forever doesn't mean it's right. Google understands the need to fraud/abuse protection in AdSense: advertisers would flee if there was no trust in the system. Same thing here: if you want to grow and keep a motivated developer audience, especially in the light of new competitors and because they're pushing Android for more device types, this kind of unethical practices should be punished.
That's my whole point here and this whole system for reviews is broken. Apple considers all reviews as part of their trending/featured/what's hot algorithms. So this stuff really matters. That plus the fact that some people really make decisions to download something or not solely based on how many stars does it have. Apple/Google should punish this kind of practices. Big time.