This is incorrect. I have three 40 inch tv sets in my bedroom, my wife plays on one pc, I on another and the tv in between us is for our alt account as we had been using xbox initially for that account until migrating it to pc. While using three xbox controllers is indeed inconvenient its 100% doable as I've done far too many times.
That said, I'm certain that well over half of the population of xi likely use Windower, if SE were to cancel their accounts and their subsequent mule accounts they may as well shut down xi as it's already on its last legs and they cant "afford" another mass ban - even if your reasoning is valid for them to do so.
If people didn't level jobs from 1-99 in one day, equip their ambuscade gear and think they can play a job perhaps the need for multi accounts wouldn't be there however that is the way people roll in 2016.
SE needs to get this game back into stores any way possible with lots and lots of advertisement, a new expansion with new zones and new mobs that are not recycled re-re-repeated mobs and include re-skinned images (bring back orig smn avatars that bogged down PS1 players for example). This game needs NEW BLOOD not just people that miss the game and come back for occasionally visiting for a few months here and there. Expand or die.