Oh people know it very well. They expected the Tower to be as easy as it was towards the end of Legion precisely because that’s when the overwhelming majority of players were able to complete the original challenges and because this is a Timewalking event which has never been difficult content ever since it was first introduced.
I don’t think anyone who struggles with these challenges in under the illusion that they can’t do them only because they don’t have a Timewalking set. They know very well that, as you so bluntly put it, “they are just not good enough to do it.” The thing is, they expected, and quite reasonably because it has always been so, that they would eventually be able to outgear or outlevel the challenge and thus get the mogs or mounts that they are after even if means waiting months or even years until they can solo it like an old mythic raid for example. That’s not gonna happen with this version of the Tower though because of the scaling and that is something which is unprecedented when it comes to this kind of PvE content.
People like you are confusing the ability to learn mechanics with the innate skill of being good at pressing buttons in rapid succession, aka being a gamer. It’s a skill not unlike mastering playing the piano and just like with playing a musical instrument you can spend your entire life practicing button mashing and never attain a level of mastery that comes naturally to prodigies. Those are the people that are completing the challenges within a reasonable time frame, the prodigies and the professionals and the rest of us just can’t hope to ever compete.
All you have to do is watch a successful challenge video and you will see that the players in question are dealing insane amounts of damage so quickly that they can ignore most mechanics and continue to dish out damage while countering the once that can’t be avoided. The vast majority of players will never be able to do that. Most folks can’t even do a mechanic while doing any other multitasking let alone dishing out top notch DPS, and that’s okay because it’s good enough for most of the game. But that’s not something you can learn with time and practice unless it comes naturally to you, otherwise everyone would be a world first raider. Unfortunately, this nuance is apparently too much for many people to grasp.
Anyway, the only tweak the challenges need to be effectively completed by a majority of players is across-the-board nerfs to boss HP and the sooner Blizzard realize it’s the only way to salvage this latest mess of their own making the better for everyone.