Here's the thing about Megas: the first one of the two introduced was Gardevoir's. Mega Gallade was a game later.
I don't know whether it's my initial distaste of the Mega Evolution mechanic, my particular initial distaste of Mega Gardevoir, or not being particularly attached to Gallade's design in the first place, but I've always been basically fine with Mega Gallade! I'm pretty sure this design was created prior to the official reveal, and although I find the partial reversion to Gardevoir characteristics interesting, I think the official design works well enough. :o
