It's a fair concern, not one I was trying to address, but yeah - no one wants dead weights who think pressing only ice spells is acceptable. One idea, that wont solve all issues (and I'm not sure if it would do most), is that certain challenging content requires you to complete what amounts to a solo test. If you wanted to do EX content in DF for example (not for any story content), then you would have to do a challenge that requires decent damage and understanding of mechanics (if you didn't stack or catch a meteor or something because you didn't understand the mechanic then the test would tell you why you didn't pass and you could try again).
In a general sense I'm actually all for "journalist" difficulty, I think everyone getting to enjoy the game, in a general concept, is totally fine. I played ghost mod (generally makes the game more aggressive / harder than the hard option) iron mode for Witcher 3, God of Wars on the hardest mode, and yet I played Death Stranding on the literal easiest option that was like "game is going to hand feed you, are you sure?"(and I still had a blast). To be honest I like the feature as a matter of time constraints, I wanted to do most of Death Stranding but don't have the time to do it on hard, while I did those other super challenges when I was far more time available. Yet.... of course this does have a multiplayer component and nothing better than someone wasting HOURS of your time because they just.. ... well they're just awful lol.
I see you concern, and I don't mind concepts that put up some barriers.. though those barriers shouldn't be overly obnoxious and they wont even stop all issues. Like some people CAN play well, and then they will to pass the test, but then they're going to leach you ayways afterwards lol. (non-obnoxious being the test for example shouldn't require insane grinding and nor should it be obtuse in how to improve, and I think for MSQ related DF content just carry your team lol, I'm thinking the savage + content).