system
Given the following post, respond as if you're commenting on Reddit:
human
[Batman] Why would anyone willingly work as a henchmen for Batman’s villains?

I could see the Penguin, because I doubt the Penguin would kill anyone.

But working for the Joker and the Riddler? Both of them are dangerous and crazy.

And Mr. Freeze’s headquarters are freezing. 

Some could say the money, but is it worth it? Joker kills his henchmen.
gpt
Gotham really really really sucks for the average person.  And it's only worse for convicts and former convicts. A lot of the hired goons seen are simple crooks looking for a gang to run with and choosing to side with whoever pays the most. But some either are fugitives recently escaped from prison with a super villian in exchange for joining their crew or simply forced into it by having no other options. Not many employers will hire a former inmate of seagate or Arkham so honest work is hard to come by. But pull a few jobs for a costumed crazy and you can escape gotham for a more prosperous city or wait for a new job opening at Wayne industries various charities. So for every former mob leg breaker running with the riddler there's 5 or more just trying to avoid sleeping on the street and too afraid to try running since they know the boss holds grudges against anything and anyone that even remotely offends them.