I am a complete altaholic usually. I got 19 characters on GW2, can’t recall how many I got on ESO, but plenty as well. Had loads on Lotro too, RoM - if I can have alts, I tend to end with an army of them 
Reading your arguments, obviously a part of me perks up - alts! As I am also addicted to housing, the thought that through alts, I could come to buy houses I right now can’t, for added decoration fun, brings tears of joy to me eyes. I also get bored to stare at the same character all the time, and we lack a transmorg system, so right now I have to counter that by owning an array of chest pieces I switch around, some head pieces too.
But alts, while a vital fun part for me, will not solve the other issues I have with the game, and there is just not enough content on offer to make me believe I’d do much with those alts, past housing and some customisation. As I imagine, introducing an alt system to the game would require quite a bit of dev time (how to incorporate alts into the faction and company system?), while right now I would rather see that time spend on fixing other aspects of the game.
Once all those things are sorted, I’d say yes, alts would be nice, and not sure what alts have to do with bots. Any account can only have one character active inside the game at any time, and if a bot is reported and dealt with, I would think the whole account gets banned (or should be). Just because someone with bad intentions would make 5 characters on their account, would not mean they could use those characters at the same time, so botting is not the issue in regards to alts.
Not certain why the company opted against alts. They may thought with their weapon and respec system it would not be needed/desired by players, but well, there are so many QoL features missing anyway, alts could be considered just part of that overall trend.
So yes, maybe in the future, but there is a lot which has to be taken care of first, and it’s quite a list already as is, at least in my view.