TechnicalBarbarity
Poser Disposer
It means bland, pedestrian, unexciting, yawnworthy in the context presented here. But if you wanna call pure DM vanilla, go right ahead there champ. It seems like a bit of a fruity descriptor to me.
Like i said it means ordinary, standard, regular etc .... look it up for yourself. And yes early Death and Morbid Angel is vanilla death metal just as early Megadeth, Testament, Exodus and such are vanilla thrash and so on. It's not that complicated.
I'm not going to bother with this anymore. Goodnight y'all.