I dont see what the issue is though. A band is a group of people that perform instrumtal or vocal music or a combination of the two. you give and argument (that according to you there should be instruments) but then you start making exceptions, based on what? people you like enough or are famous enough that you dont want to disregard them as a band?
I guess saying music group instead of bands will make you feel better. For most people it is the same though, I think for the ones that feel that a band is about playing instruments grew up with a lot of "I in a band" "Are you in a band?" "I wanna be in a band" And in all those cases it is usally meant a formation with a singer, a drummer, and 1-3guitar players and maybe a keyboard player. The standard band formation.
But you cant keep on describing "a group of people that go out and perform and make music together" people just call them bands.
I found gorillaz to be quite refreshing too. ( Older stuff probably too, but I wasnt around when they showed up, so not aware of the impact, but for instance heard hendrix was pretty special and can see how pink floyd was quite different from other bands. And I am sure there are more cases)
Ow and if you want unusual territory. Check out apocalyptica. Metal on 4 cellos, they are pretty damn awesome, atleast the concert I saw of them.
In case of music, yes that isnt a specific male dominated area, so there cóuld ve been more women. But to demand it... what is that gonna do? Noone is gonna complain, ow there are more answer starting with M than with S there should be more S on the quiz...
Regardless of what people say men and women still arent treated equally. But overcompensating to having them more on a random quiz (as opposed to quizzes that are about accomplishments, inventions, bravery etc) is not gonna do anything and feels rather fake to make such a fuss over.
I have much more to say about this, but this isnt the place, but I had to get it of my chest.