Of course that is a risk, and it will to some extent happen. I’ve already said so in the post myself. Does that mean that blizzard should nerf m+ to be equally easy to queued content, as that would reasonable make more people play m+ and generate more revenue for blizzard?
No.
Challenging game modes should be challenging. If you can’t beat the game, get better or play something else (yes, something else can be either a key level you’re fit for or another game entirely). They’ve made 20s key way too hard for me and most of the playerbase, yet we’re still doing m+. It’s fine to not be the best, and if they can’t learn how to play to succeed in even a +2, then m+ just isn’t for them. That’s fine, there’s other content, and in worst case there’s other games for them to play too.
Where should we draw the line for how easy m+ should be? If making content defeatable for most people is what generates the most revenue for blizzard, m+ and raiding should be nerfed to heroic dungeons/lfr levels already.
I don’t get why you think that there’s such an extreme amount of DPS players who are incapable of learning mechanics and rotations to just 70% (just a numbers example) of what their role is capable of. WoW players aren’t inherently dumb and incapable of getting better at things.