He wrote The Book on rendering performance. Michael's super optimized x86 assembly routines for lighting and texturing is the reason we can run Quake on toasters.
Anyway, I don't think they should hire Casey. Specially after that demonstration of not understanding the big-picture and not being a team player...
The 'big picture' he hasn't understood isn't just about text rendering in this instance, though. It's also a picture internal to Microsoft that motivates their commitment to certain libraries. I think the disconnect is to be expected, given that he's not currently at Microsoft. It may also be that some of those commitments are not as well motivated as MS thinks (i.e., maybe the additional maintenance burden of some specialized text rendering libraries for the simplified case of terminals is not so terrible and justified by the performance gains). I don't think this shows that at Microsoft he'd be unable to have a good sense of 'the big picture'.
It's also not clear that any of this shows he isn't a team player. The Windows Terminal developers are colleagues of his in the distant sense of 'fellow developers', but they're not 'his team'. He doesn't have pre-existing relationships with them. And his frustration was in being told 'this cannot be done' in a way that was insufficiently clear and convincing to him and came across as condescending. I think it's reasonable to be frustrated under those circumstances, feeling ignored and maybe also like someone is bullshitting you. I could see the interaction being different if Casey had a different relationship to the other developers and they were more invested in trying to loop him in on their whole suite of platform commitments that ground (or trap) them in the current design, especially if he felt like advocacy for alternative commitments (e.g., to maintaining a separate, simplified stack for rendering text on the terminal) might be reasonably considered.
I'm also sympathetic to some of the MS devs here, because some of Casey's tone could have been taken as suggesting that they weren't really making an effort with respect to performance and that could be insulting. I don't think it was necessarily wrong for them to bring that up. But I don't think Casey was abusive, either, and it doesn't seem like anything that went down in that thread is beyond repair to the point that the people involved in the discussion couldn't work together.
If Casey were interested in working at Microsoft I think it'd be silly to rule him out as a candidate based on what we can see in that thread.
In fact, consider the hypothetical of: what if Microsoft had hired Casey Muratori.
Do you imagine they’d have put him on the console team?
I mean the Windows console, not the X Box console, or the Minecraft console.