Why is it a problem? Sounds to me like emulation is a very good fit for AI.
I can imagine some people feel like it's cheating because they did it the hard way. I have much respect for those people and their skillset and I hope AI doesn't discourage them.
They don't normally give a reason. Just picking a few random examples
https://old.reddit.com/r/emulation/comments/1wbapys/zevora_e... https://old.reddit.com/r/emulation/comments/1w8b6rk/ruzu_is_... https://old.reddit.com/r/emulation/comments/1vz9na6/pc_ports...
I think another problem is: vibecoded emulators (like this one seems to be?) are likely to be a stunt, a cool project, but will not be maintained. Upstreaming this to qemu requires at least some human effort, and it is not very likely to happen. So we are left with a cool trick.