Kant was right. End of story.
Fascinating how much you want to close the discussion, you just quote some old dead dude. Afraid to lose?
Please! Be my guest. Do go ahead and show why Kant is wrong! But don't be surprised when you fail, just like several hundred years of others.
Critiques of Kant mostly rely on the introduction of a logical contradiction and then the critiquer dancing around and praising how clever they are. The rest of the critiques of Kant pretty much boil down to temper tantrums, hissy fits and name calling.
BTW - The reference there goes directly back to what Severian had brought up with obligation, i.e. duty. You need to read an understand Kant at least a bit though to get the reference and how it applies. It's not directed toward the broader discussion. Well, until you decide to apply it like that.
As for him being "some old dead dude", you appear to be showing a general lack of knowledge about moral philosophy. Kant is the giant.
the problem with kantian ethics is that if you follow the categorical imperative, its very easy to end up in a situation where you can't take any actions, but by not taking any action you have chosen not to do so, and therefor have chosen the action of non-acting, which is immoral. When kantian ethics are faced with a moral dilemma it fails horribly.
rational egoism or utilitarianism does not have this problem, they only try to maximize happiness(either your own, or a group's).
Kant is wrong.