In my opinion no, civilians arent able to get c2 and their nearest equivalent would be remote/timed explosives, allowing grenades to open doors would make other explosive methods practically useless as grenades are quite a lot cheaper
The big benefit of timed/remote is the displacement of props, although I don't know how realistic it is for frag grenades to blow open a metal door like that of the Bunker
We can easily modify what all the timed/remote ones do as well as make it so grenades would not open metal doors plus their range would be tiny by comparison. Also grenades themselves are not very cheap so it's not the most economical decision to use to do this task. It's more so to have the option possible.
Part of my thinking for this was simply that C2 can be detonated safely nearby as it is a "shaped" charge designed to blow open a door. A grenade on the other hand requires you to clear the area. Crowbars and lockpicks require you to put yourself in a vulnerable spot though which often results in wallbanging. So I'm fine with however people vote on this.