- I still don't understand why some games are distributed as multiple zips? Is there a reason why they can't be combined?
They can be combined. And used combined. Or not: "merged" (what you're talking about), "split" (the most common), and even "non-merged". You can merge your zips if you want. (I'd use cmpro instead of doing it by hand.)
The reason the most common distribution is "split" is it takes up less bandwidth in two ways: files (ROMs) shared between two parent/clone games only need to be downloaded once (in the parent zip file), and you don't need to download any of the clones if you don't want them. Also, if just one of the versions has one of the ROMs changed (fix a bad dump, for example), the whole merged zip would need to be changed, instead of one smaller zip file of just that version; effecting any internet caches that might hold them (I'm not talking local caches, but ones that help speed up comcast, ect).
Not having to download the clones is the biggest reason split is used so much, but you can find merged sets out there.
It seems ridiculous for every user in the world to have to customize their front end game list menu to hide unusable zip files.
I think you're mixing different concepts, and blaming mame's multiple zips.
A. By "unusable", I think you mean ones you don't have? Whether a FE displays all the possible games (6100+) or just the ones you have by default is
up to the FE not mame, nor if you have merged sets or not.
B. If all versions of a game were in a single zip file (aka "merged"), many FEs would still show all the versions unless you set it differently. (I can't tell if this is a problem for you.)
C. "Mame is not about playing the games; it's about documenting the hardware. Playing is a nice side effect." This mameDev's official stance, not my personal view. This means any complaints about how hard mame is to use will not be listened to by those who count the most in mame's development.
D. If the arcade game had different versions with significant differences, mame will (try to) emulate all of them. The "user" reason is person A remembers playing version B, while person X remembers version Y. The real reason is there were different versions in the arcades, and mame wants to document all of them.