The problem is, and this is important: you cannot control DF. No matter how many times you try and post on the forums or yell and scream it would make things easier. Therefore you shouldn't try, instead you should encourage people you do know to NOT df content if they are new. But practice with FC people or use PF.
In my experience, most of the people with attitudes like me do in fact do the hard content. People who stop at the early 50 dungeons usually don't play much, or only craft. So they are unlikely to even be involved in a discussion like this.
You seem to miss the fact I don't care if other people beat the content first. Fundamental difference. We do not think the same. You are trying to project your opinion and play style on others, that do not share that opinion.
For me the fun is challenging myself and determining if I can come up with a strategy to solve content, not to find a strategy online and follow it. You have a very different perspective. That is fine. I really don't care.
Why does it matter if a strategy already exists, even the same one I come up with? That is irrelevant to if I personally (and obviously in conjunction with a group of like minded individuals) can come with said strategy, rather than merely follow it.
I also enjoy going in after I have found strategies that work, and continue to try different things. By your logic, why would I? I already know how to beat the content with one strategy. What value in intentionally throwing out the method used to win, and trying to come up with a different one? Clearly I don't think that way, and nor do those I typically play with. For us it is about the challenge not simply the solution.
I am stating that you cannot control who is in DF. You cannot. No matter how often you encourage people to watch a video and read a guide first, including on the forums. You cannot control whether they actually do. So if this is something that frustrates you, then avoid DF. You cannot control what other people do, only what you yourself do. The developers have also stated that kicking people for being bad is an abuse of the system, so that shouldn't be on the table either. Therefore if you are going to use DF, be okay with the possibility of non-stop failure and rare success, or don't do it. I am not encouraging people to go in blind to DF, nor am I encouraging people to watch videos before hand. Rather, I am encouraging people who go into DF to expect other people who are at different levels of preparedness and experience and deal with it.
As for me, I don't DF anything new anymore, why would I? I have an FC and we also now have PF to form groups with even more like minded people.
When this discussion has come up with new 50's in FC, I tell them that they do not need to watch videos or research the hard content, but that if they don't it may take a longer before they are able to beat (or reliably beat) content, so they should play whichever way fits them best. I do discourage them using DF if they have a problem with failing repeatedly, because it is going to frustrate them. I will never say people should conform to either mindset. Instead they should do whatever fits them best, and just group accordingly.