More options to play stand your ground is good, but if adding it to all maps means all options to play vanilla maps without it have been removed, I don't like the sound of that at all.
Ignoring it is an option, yes, and that's fine on a private server of people all either wanting to play it or ignore it, but when all public servers will have a mix of people interested and disinterested, this hard-set team-effort feature will just be an unsatisfying disruption to things, half the time.
--If you don't want to stand your ground, but your team generally does, you either ruin their fun by ignoring the sub-objective, or you can feel obligated to play the way you don't want to. For example, a gunslinger getting little use out of his speed bonus because he's stuck in position, trying to headshot zeds while his screen is all orange and the zeds are all stumbling and panicking because the firebug has to be nearby, too.
--If you want to stand your ground, but your team doesn't, well too bad, better luck next server.
--If you and the rest of the team want to try to stand your ground, but your team doesn't want to or can't specialize their perk/equipment/playstyle in order to survive standing still while six QPs and two raging FPs spawn 15m away, you probably can't carry them, and there will be no option where stand your ground is worthwhile to attempt in latter waves.
These problems don't appear too much on Krampus's Lair, because it's currently one of few options to play stand your ground, and it has always been a stand your ground map, so most people not wanting to play stand your ground properly will go to other servers, vote for other maps.
However, these problems are already appearing with the West London map port that has stand your ground. Some people join for the classic map and want classic natural gameplay, while others want to play the sub-objectives, and that's a mess half the time: how adding stand your ground to all vanilla survival maps will be.
A server setting allowing stand your ground to be disabled, and a respective filter in the server browser for that, on/off/either, should be included. That way, when you join a server with it enabled, you can expect lots more teammates to want to join you in the sub-objectives, and when you join a server without it, it's no concern at all.
