>> And since mechanical, mahjong, gambling etc. were mentioned too, I support that the official release builds have EVERYTHING on. MAME is not an ethics school (like the old ban of gambling machines), it is EMULATION software.
You seem unaware of how easy it already is to compile MAME, and how much more simpler yet with more options can be made. That's what changes everything.
MAME should not even release any binaries. What are you making issue about is just a bunch of options set as default, or not. Just a bunch of check-boxes that needs to be checked or unchecked. I'd set them all to unchecked by default, so that "official build", or better to say "default build" you can make with "official compiler" is the smallest size of all.
It should be about "official compiler" and "official source code", not about "official binary". Official binary you get by using official compiler and official source code, no matter what game drivers or extra features you exclude.