funnily enough, the first public version of 3DO is now available on the MiSTer (se: https://www.youtube.com/watch?v=pyew7oHGyNE) - its doesn't seem perfect, but its not nothing!
1. There’s not that much interest in general, most anything interesting got ports to other systems.
2. There’s no such thing as a 3DO. There were several, and all of them function slightly differently, usually an irrelevant difference in functionality, but if you’re making an accurate emulator it means you need to make a dozen emulators, actually.
3. Apparently the hardware is just weird in general. See also the N64 for an example of a system that suffers from this.