I picked up Shulk at launch, and managed to get pretty far in For Glory in the early days (acting like a noob Shulk, running Buster against combo-heavy players, never trying Speed/Jump MArts - but I
did have the sense to immediately see Back Slash as a surprise tool, punishing zoner/gap closer, and to avoid projectiles) but those tactics started me losing, and I've finally stopped lurking these boards (knew about vectors going in first time, now I can't DI in P:M anymoar
) and am planning to git gud.
Also, Forward Vision kill > Falcon Punch. There. I said it.
But, yeah. Learning curve. That and the fact that SSB in general kind of encourages you to pick your favourites, and Xenoblade Chronicles is far more obscure than the likes of The Legend of Zelda or Pokémon.