useful features like guild training hall
GTH is far from useful, tbh. It saves some time checking damage if you happen to be doing research or tests, but for the most part it's largely useless.
or forcing us into CR farmers
If yu have 400k upkeep, then the odds are you have a large guild with a lot of people. 40 people doing a single FSC run (or twenty people doing two) will pay virtually all of that upkeep, and a large guild shouldn't have too much trouble getting quarter of your number to do 1/2 FSC runs in a full week. If you're too busy to manage that, then you have no business playing games in the first place.
If you don't have 20 people in a guild, then you really shouldn't be landing yourself with 400k upkeep, esp. since all of it is cosmetic. The GTH is about the only unique feature in the GH (that you can't get w/ a 10k upkeep GH) and is, as above, pretty useless anyway.
Someone told you the Autogun is bad? It upgrades to be one of the most powerful weapons in the game at five stars, so that's a bunch of lies.
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Especially in tier one, where mostly anything will work in PvE.