The majority of the complaints you see on the forums come from the same place, frustration. A lot of this frustration comes from history repeating itself, its Vermintide 2 all over again.
The community expected to be able to do cata on release, none of them wanted to accept that it was a sequel, and had changes, and improvements, because you know, why make a new game, if you are not going to change anything.
Instead they queued for Cata had a really hard time, and embarked on a similar crusade as the one that the community waged on darktide. Why because once again the community made the same mistake.
Veteran Vermintide players refuse to submit themselves to the learning curve, and gaining the necessary experience/confidence, to overcome the challenges you present them. This time the issue is 10000x more apparent, and 1000000x more damaging, why because the community is much larger, and on top of that streamers further magnified the issue by making the same mistake.
Educating your player base is not your job, and telling them this, well it is impossible nowadays without you getting crucified by the SJW mob. What you can do is set expectation of how you expect them to play the game, and what there minimum performance on a difficulty should be at.
So I would like to suggest a score/rating system similar to those used in Resident evil games, but with a focus on what would make a squad stand out from other squads if you had to pick one to get the job done. Squads can be rated from a “D” to “A+”(SSS+?) by meeting a minimum standard in the following areas:
Mission completion time (because we have to get in and out fast to not draw more attention)
Total Enemies eliminated by squad (because skulls for the skull throne)
Hazard pay for the squad (cuz people need reasons to kill monstrosities/DH)
Teamwork (Use of cohesion etc. etc.)
Theres bunch of other stuff you can prolly factor in, and what not, but the idea is to promote two things, working as a squad, and meeting a minimum standard before moving on to another difficulty.
Why? because theres a ton of competition, and the detriment to players experience, in particular those that have put in hte time, learning to play your game, is significantly higher, and does a lot of damage to player retention on the long run.
How does a system like this help, well no one will want to say “I play on damnation, but Im always getting a D rating in missions”. If you also add scaling rewards so that a higher rating equals higher plasteel/credits multipliers, it will be blatantly obvious to anyone thats spending an hour in damnation, that they would be better off and enjoying the game a lot more playing on a lower difficulty.
It is also a system that has worked for decades, across multiple genres, and one that players are used to. If you think about it, it might provide a solution to multiple problems, and line up a few ragers to hit with one Box.