Eviolite a shit. Even Chansey isn't broken with that [it's very good, but not broken. And who has a team without knock off nowadays]. This is not the thing. Eviolite Lucario? Shit. Eviolite Houndoom? Shit. Eviolite Mawlie? Shit. List goes on.
There are some pokemon like Lati duo, Sableye and Scizor, Diancie [huehe] - that would be broken, right. But that's minority.
The real reason is very simple. Megas were designed to refresh the meta. One, super powerful pokemon [at least on paper], the 'boss' of your team. Say we drop mega evolutions. All megas are regular evos now. Life Orb MLucario? Choice Band MScizor? Sashed MAbsol? All on the same team! Holy shit, that's not what we want, huh? Ok, so let's be gentle with stat boosts, maybe +40 instead of +100. But wait, now meta is the same as it was last generation, just without weather wars. Boring, huh?
You get it now, people? It's not about eviolite at all. [well, ok, it is also about eviolite, but that's not the only reason - and not even the main reson].
That being said, some of the megas definitely should be regular evos [houndoom, ampharos, etc] and I am sad about forfeiting cross-gen evos too.
But get your facts straight.
