Saying Crawl is like Nethack is a grave insult indeed. I think you may just not like RPG's, which is fine.
Endgame in Nethack involves getting 7 candles, killing Vlad and Rodney, blanking all your scrolls, writing a bunch of scrolls of enchant armour and enchant weapon, getting DSM, getting speed boots, getting a proper cloak (probably MR, the rarest kind), getting GoP or GoD, getting the correct helmets, diluting all you potions, doing a water ritual to turn all your water into holy water, blessing everything by dipping it into your holy waters, enchanting all your weapon and armor, rereading and ditching all of your spellbooks, writing a bunch of blessed scrolls of genocide, writing a bunch of blessed scrolls of magic mapping, writing a bunch of cursed scrolls of teleportation, writing a bunch of cursed scrolls of genocide, writing 4 cursed scrolls of gold detection, writing a bunch of blessed scrolls of destroy armor, confusing yourself, reading the scrolls of destroy armor while confused to fooproof your armor, genociding L, genociding H, genociding ;, genociding M, reverse genociding nurses, reverse genociding unicorns if you need to raise your luck, reverse genociding tengu until you have intrinsic teleport control, polymorphing into a xorn so you can eat rings and amulets, performing alchemy so as to upgrade your potions, and, finally, if you still don't have all your stats at max, drinking from magic fountains.
There may be more, that's just off the top of my head.
Endgame for Crawl is deciding which weapon you'll use, deciding which branches you'll choose not to do and doing the rest, deciding what armor to wear, deciding what rings to wear, deciding what amulet to wear, deciding which spells to learn, deciding what other rings, amulets, and weapons to bring with you to switch as needed, going back to any troves or ziggurats you skipped, and deciding what skills to turn off and on.