Yeah, jinjer is bomb :)

The usual go-to is "but that's not real metal" with some degree of exaggeration so that it's obvious it's not to be taken seriously. There's the occasional "it's okay, it's great that there's bands for little girls to like", or some equivalent. And a personal favorite, "poseur /s".

I tend to call it a gimmick when the way the sing/scream is done never serves individual songs. But, you're right, it's probably more of a difference in songwriting and arrangement than the band just trying to jump on the bandwagon. I can't think of any examples off the top of my head because I tend to just move on without remembering anything other than the fact that it didn't work (for me anyway).