Assuming true that bots comes from free trials
That is probably a wrong assumption. Anyway, as long as bots don't do anything that effectively hinders other players' enjoyment of the game, I personally think it's fine, even though I never used a bot myself.

I mean, if someone wants to level another job but doesn't want to waste dozens of hours spamming pltd/dungeons, I think it's fine to use a bot. It's not like this causes any problem for other players. However, people that use bots for crafting and flood the market with several 99x stacks of infusions and other things...that is another story. But I suspect that most crafters are using a bot nowadays since crafting rotations are so stupidly long and time consuming.