I was going to bring up the issue of arbitrary diffuculty and time sink again with the end grinder.
The general consensus is that portals are OK/worth looking into because because all that time adds nothing to the game.
One justification I have heard used (though not needed in my mind) is that it's OK because we don't have a real perma-nether to use for the decreased travel time.
I think the same logic should be applied to the end. The end grinder is great, and usually a big part of any survival server.
Resetting the end every month is... not exactly a bad thing, but I realy don't see why it's a good thing either.
Unless there is a demand for obsidian and dragon eggs, I suggest a less frequent resetting of the end.
It's a time sink that adds very little to the enjoyment of the game. If a justification is needed for it... well... vanilla MC doesn't reset the end sounds good enough.