Mega evolutions generally gain a ton more stats overall than a single evolution does, so they had the potential to help balance some weaker pokémon that never got used. And while some weak pokémon were given mega evolutions, it feels like at least 50% of the chosen pokémon who got mega evolutions didn't even NEED the extra strength compared to others. Garchomp? Gengar? Alakazam? Tyranitar? Blaziken? Gyarados? Heracross? Scizor? Latios/Latias? MEWTWO??? Holy crap, none of these needed mega evolutions in terms of balancing (though I'm not saying that their actual goal was to balance).
While I'm against the concept in general, if they were absolutely going to push for this new mechanic, they could have at least put more thought into WHO would get a mega evolution. Houndoom, Banette, Kangaskhan, Mawile, etc...THOSE were well picked. They were not competitively viable pokémon, so the extra boost gave them some love (especially Kangaskhan, from my understanding, he's broken in his mega form). Still, I would have preferred a straight up new evolution for them instead. They had an evolution "slot" (weren't a Stage 3) available for a normal evolution at least.
Now after complaining so much, I should clarify that I haven't even spent much time with mega evolutions. In other words, I'm speaking more on the general concepts but can't say much to the actual execution. Perhaps someone who's used them a lot could explain what makes them cool? What new depth do they add to the game? NPC said that many megas change their playstyles. In what way? I'm willing to be convinced that my "preconceptions" are flawed.
