Rates high, so ppl reach end game too quickly
Some classes are broken and most ppl pick those classes so they find game too easy
People go straight to final gear instead of following a natural progression so they got nothing else to do
The suggestion is fine but don't assume everyone tryhards the game to go straight to end game gear. We always have the option to take things slowly as it's somewhat intended to be, do a proper progression, pick a lesser but fun class, etc. Rather than implying there's something wrong about the game or server, this is more of a 'please add harder content for the few of us who got nothing else to do'.
If custom endgame content is added it'll also eventually turn into a 'im just farming and there's no challenge' to you, and then it'll be a smaller minority asking for even harder content. Those coming from dead server know that very well.
ps: also, too much text and not much said, please summarize more!