Yeah, but they were winning. Gaethje, for example, walked through his opponent's souls and finished them, they gave their all and still got beat. Meanwhile, besides Khabz, neither Doostin or Eddie felt like winners for multiple weeks after their Gaethje fights. Both said it was a miserable recovery. They weren't at football games the next day.
So it's not the same as just getting a one sided beating before an official L.
As for the OP, I blame the corner. If it's going one way with no hope in sight - just get your guy out of there. Fighters themselves will rarely call it quits, but I wouldn't blame them. Like Nick that same night - I had no interest to see him get mushed for 3 more rounds. He caught enough, that's enough. Live to fight another day. If some kind of honor and what will others think is the reason not to - people will shit on you and discredit your achievements in the future anyway, so just do what's right for yourself.
Winners quit all the time, they just quit the right things.