The original plan was to limit to level 80 (not misspelled) so expect no support from me on this. The chest also came years later ─ if memory serves, ~7 years gap, definitely not related.
The world has a dozen farming areas, incl. Tulimshar's Snake Pit which has a good exp ratio. (At least on paper, never been there, I'm horrible with mazes ─ which is weird considering how many mazes I use in the game).
The idea for the Crypt was to add an extra farming area for high level players. It was originally intended at 90+, then 80+, then eventually devs agreed on 60+ (note in the post below that 60+ is below the level expected to fight with the monsters).
If you're below level 60, go grind in the Graveyard. And the area is good ─ WarriorWorld got level 135 without ever setting foot inside the Crypt, and remains to date not only the first but possibly the only player to reach that level cap. (If anyone else does, talk to me to receive the Book of Floyd/Maverick, though).
PS. I understand the logic ─ crypt boss fights can be fun, and they're easier to start than Candor ─ but I still don't think changing level requirement has anything to do with it. It's like setting the house on fire to avoid the dark pest ─ even if effective, it is not worth it.
PPS. Don't forget this is TMW, where good ideas are skewered for the greater good. If it starts by reducing the entrance level, rest assured in a few years (assuming TMW Classic is still running by then) you'll have people complaining Crypt is too hard and have developers FOR THE GREATER GOOD! nerfing the monsters there. No wait. They already nerfed the monsters there. Nothing in TMW holds true to its original design (much to Hocus resentment, as he made the original design for Boss Medals and they turned out very different from it).
TMW Classic is a design-free game. So maybe devs will agree with you and remove level requirement to enter Candor Cave and Crypt (lets mention Candor Cave in any case, "to keep out new players = Lv 40 cap" makes no sense). I'm not one of said devs, not anymore.