Normaly I'd say "Boo you for saying quit the game if you want to change something" but

This isnt a "shitty game design". I do not know how they decided for 15 minutes, nor do I care. 15 Minutes are nothing. in Sea going afk for 15 minutes at a random place can still kill a 95. There are enough mobs to play with that also give exp and with some luck some drops for sea gear.

What IS falling under shitty game design, including areas that put one part to baby mode but puts others to ultra hard mode. Gaining levels is easy now, yes. Doing early genkais became harder thanks to the mobs that can easly kill a 95 in an area like Crawlers Nest. it takes of the fun part of doing early genkai. while it WAS annoying to get ancient papyrus and exoray mold thanks to low drops, now you need to watch out as helper not to get eaten by mobs that normaly would have been no problem

If waiting 15 minutes is such an issue to you, I hope you never get stuck in public transport or in an elevator. You probably will go insane.