Well unless we add a reverse 'look up loose file in softlist, attempt to work out proper softlist entry' type logic it's always going to come down to really ugly hack code (that sometimes the ROMs intentionally cause to fail to fool copiers etc.) and even that kind of reverse lookup is unreliable.
and even if we add that logic, it becomes problematic as soon as you're dealing with merged roms instead of split roms or cases where the loose ROMs are byteswapped vs. the proper dumps. You start to have to check a ridiculous number of possibilities.
MAME has always favoured trying to offer cleaner code, not code full of detection hacks.
Unfortunately the scene is 'broken' in the sense they'd rather keep bad stuff because it's convenient, and do things the wrong way because it's convenient, leave the burden on the developers to have a sky high pile of hack code, exclusions with built in patches to compensate for bad roms etc, because it's convenient (for end users)... MAME has to try and encourage more positive models I think, it's what separates us in a good way even if we do get hate for it. I'm not sure sinking to the same lows is positive, even if it's more what people expect.