That and the fact that amiga was clean room design. IBM Pc was already old and even x86-64 won over itanium. Backwards compatibility has a cost but also gains. Amiga wasn't even compatible with c64.
Sure but "pc" at the time of amiga was already pc compatibles and at backward compatible with xt and IBM PC. Besides amiga was very optimized for 2D graphics. 3D story has been less rosey. But I would seriously welcome a new amiga. That wouldn't mean a specced up amigaos running pc. That would mean a radical new mobile architecture. Or Vr machine. Some fresh air On a radical, alien architecture. Belt CPU ? Gpu/CPU à la xeon phy ? Ram only? Dunno. Something crazy.