You can stop reading, but the game is finished. There's no reason for me to play. Every other class is suboptimal and clear times are much longer.
Challenge?
Self-gratification?
ePeen?
People played sub-optimal kits in ME3MP, giving longer clear times, and less efficient runs - even after maxing their manifest. Using the most overpowered kits and weapons was only an option, and not enforced upon one as a player.
However putting a video up of a level 1 Volus Adept with a Shuriken, and clearing Platinum was a guaranteed way of getting some kudus, vs maxed GI with <insert OPness here>.
Personally i'm really enjoying playing the Katari: i believe this is generally considered a weak and sub-optimal kit, but i am having more fun than playing with other kits.
Sure i get people leaving the lobby as i enter, or kick votes, presumably from those only wanting optimal kits and fast clear times... but whatever i take no offence, as they should not from my choice.
Peace, love and mung beans baby! 