Only a Sith deals with absolutes. Specially for a 7/8 year old game. Gren spam WAS a thing. Which will probable never return unless something weird is done to G43 package.
It was indeed, but every single time there was a quality cheeze attached to it.
March deployment, sure gren spam was perfectly valid and no wonder, they rolled even guards with impunity and G43.
Same for current VSL.
Any other time I remember there always was HMG or sniper or turbomortar behind it, so not exactly grenspam.
Gren spam was valid option pretty much only at times when grens were confirmed to be OP and it all returned to normal following patch anyway.