Title says it all.
Not that I have a problem with challenge. My concern is that people who were still working their way up to do, say, +20 or that range, are now having the problem of getting their progression essentially reset.. Multiple times.
You don't see them buffing them raids as the tier progresses.
They talk about the rewards and power curve of players.. As if they didn't think players would become powerful enough to trivialize lower level content.
I am not against keeping the M+ at a certain stable rate of difficulty, which may include slight increases to the difficulty curve, but this latest change of adding the equivalent of 3 key levels for all difficulties will not only harm those who didn't/weren't able to take advantage of the initial power curve or HN gearing, but will also punish those who are putting energy into M+ as personal progression.