Why so many bot on my server.

[KageTokage]

Those bots are typical gil farmers and are defined by their gibberish names and use of teleport hacks. They're also generally BLMs and BRDs, though I've noticed a strange trend of them being WHMs instead of the latter recently. Simply doing a search for level 1-50 THM/BLM, ARC/BRD, and CNJ/WHM will reveal just how many of them are present on your server.

I don't think it would be a stretch to say that every mid to high population server has a constant stream of them being created/deleted as they repeatedly complete the MSQ.

There are several things they could to do stop them (Making enemies go invincible/reset if they can't reach you for a prolonged period of time would be an easy one, as they rely on their ability to teleport under the ground to kill all of the dungeon bosses without tanks/healers), but they don't for who knows what reason.