Let me be more precise:
You CAN play an esports title casually.
But you CANNOT play a casual game as an esports title.
It's that easy. It simply does NOT work to try to appeal to both esports and casuals at the same time. The only thing you CAN do is to make the game for esports and then guide casuals into the esports side from the game.
That's not true, not true at all.
I posted a documentary about the smash bros: melee scene. The game's lead designer and director has been quoted that he designed the game to be a party game and Nintendo has issued law suits to people creating content for the game or streaming the game in the past.
I'll link to it once more in the hopes that people who vehemently believe what I quoted will change their opinion.
http://www.youtube.com/playlist?list=PLoUHkRwnRH-KTCH3tJ9WvsWWPEgUu-y6d