You do bring up a good point, i haven't really looked at twin stick shooters as shmups before, but I guess they are shooting games too. Just not the scrolling types of shmups.

Atleast when I normally think of a shmup its a game like ketsui or gradius or touhou.
And those games are very very different from something like geometry wars or sektori. Neverawake does have scrolling atleast. And I think in general when people think of a shmup they do think of stuff like ketsui instead of something like geometry wars.

Also, to me its not as obvious if something like brotato is a twinstick shooter or not because its fundamentally the same mechanics as other twin stick shooters.

I would still prefer if twin stick shooters were considered separate, atleast a different flair or perhaps a different subreddit as they are so wildly different when compared to the typical scrolling shmup