I absolutely understand where you are coming from. I acknowledge that this is 95% about Conor being a friend of mine, and 5% with me admiring his toughness.
I would not encourage a student of mine to have the same stance, I have had to tell some of them that they should tap - at least for low-level tournaments. For ADCC, maybe it's worth - I don't know. But Conor Heun was fighting for glory - 15 minutes to glory, that's how he described MMA. He was trying to prove to himself, first and foremost, what he was made of - and that was sterner of stuff than most of us.
You are right though, tapping is perfectly acceptable, and preferable in most cases. There's a line between a sprain and a break - and I think most fighters would allow a sprain.
On the other hand, I know a UFC fighter who vowed he would never tap to a choke but did when he was finally caught in one because he felt it a sign of respect to his opponent. I admire that sentiment as well - tapping is a sign of respect.