Why garrys mod haven't a VAC bans?

I think theres not that much of "hacks" for garrysmod so valve decided just to leave garrysmod without a vac / ban sytsem

V.A.C would block every addon of scripting like E2 and such

Because it is inefficient, besides there are moderators who follow the order.

Because Valve is the worst anti-cheat ever made ^^

and someone already made a better anti-cheat for server than vac itself.