Don't get me wrong, I enjoy a bit of that Blitzgrieg TvT mission as that actually has an objective. What annoys me is the people who cry that it's in first person only or "why does this server not have tags above team mates?". They simply refuse to try and learn what to do. Instead they sit there and shoot their own team in the spawn!
I know the simple solution is to password the server but we need to keep it open for people to come in and try different missions.
I understand, it's why I rarely if ever play on public servers.
Everytime I do, there's someone with an awful connection, desynching everyone, loads using ingame von when they don't know it or just being obnoxious and having to keep on muting, then there's what you mentioned about, amongst the leagues of "hackers" which, while I understand BE isn't the best and not enabled; I join a public server and instantly there's one.
It's why I don't, why I stick to a dedicated arma community and stay there for infinitely better PVP and COOP missions with zero fuss or chaos
The biggest issue is people expect the game to be there for them ready to go on a random server, not realising your experiences vary so vastly from place to place.
It's not the game that makes it all great, it's the people you play with, find good, talented and mature people and go from there.