On one hand, this is kinda cool. On the other hand, why would I want to run MacOS in the first place? Modern versions I mean. With the deterioration general quality, Liquid Glass and all that.
The only reason I do that is because I _have_ to do that due to MDM and the fact that Asahi doesn't do the Standby. Excellent hardware, bound by a sad OS.
Why take normal hardware and add a sad OS without being forced to do so?
I suppose "for the sake of it" is a good answer here. For the fun of making computers do something they really do not want to do.
Other people are not you. They have different needs and different likes than you do.
An example could be as simple as somebody whose Mac broke and needs to use MacOS specific software and workflows, but can't afford to get a new Mac.
The author seems to have done it, at least in part, for the purposes of iOS development. That seems to be a bit more compelling than "because you can", though Doom running on refrigerators and pregnancy tests shows that's already plenty on its own.