My point is not that the "the game should be difficult for people who reach level 81"
My point is the complete opposite. Please re-read my post. My point is that the game can be difficult with bosses until you reach about level 40 or so. Then it because easy due to power gaming.
My point is the complete opposite of "the game should be difficult for people who should reach level 81". It should be difficult up to a point until you reasonable max out your character which is way below level 81.
So it is a good design. It appears you misread my post.
Yes, your point is what makes it bad design. The game allows the player to reach level 81 but offers no challenge incentive to even reach beyond level 50. That is bad design, to give something to your players without balancing it into the game world. This design is essentially giving the player the Super Star in Mario and having it not be temporary nor having them die if they drop into a pit.
I read your post perfectly fine, the counter to your post is Design 101: you don't give something to a player if you expect them to not obtain it, and you definitely don't give something to the player if you don't design the game to include that design.

