Lol, yes, nostalgia is the main theme in X & Y. Probably to please Pokemon veterans and/or to get more money.
I'm actually OK with this as this is their first try...
(But they never should have given Charizard 2 Mega's )
This I agree with. I know Charmander, more so, Charizard was explosively popular back in the day but I dunno if it warrants 2 mega-forms, meh.