I would disagree with you OP. You state that League of Legends is balanced around professional players. It is not… What makes LoL so succesful, is the fact that it is so simple, free to play and easy to learn/pick up game. The professionals are the ones who take certain heroes and push em to the limit, which gets nerfed/buffed based on feedback.
Same thing goes for GW2, casuals are the ones who will support competitive play and eSport if they can play themselfs, enjoy the game and enjoy watching others play the game. So it should always be accesible and easy to play for casuals, where as the pro’s as you put it, can take it to the next level and push certain professions to their limits.
Keep in mind that LoL is closer to GW2 than WoW. Even tho though is an MMORPG, many pro players look at this as more of a MMO-Moba, due to no trinity and so forth.
I believe, catering to casuals is the smartest thing you can do, because a professional player, will always find a way to play the game or a profession to their highest level and push it to their limits to succeed and achieve stuff that a casual wont be able to do.
Look at lowell as an example, i play an engi and usually have no issues with thiefs, backstab etc – however, due to lowells skill and new approach at the profession, he outplays most bunkers, yes guardians included, because he pushes his class as far as it can go.
My 2 cents.
