The joys of having children. I can deal with the hard questions: where do I come from? Where is the moon during the day? What happens to the light when you turn it off?
But - where DO baddies get their goons?
My eldest is playing DC heroes and wants to know where The Joker, Bane and The Oenguin get their henchmen? Why do they help the baddies? ("To get money from robbing banks" dies not help, as "but why? They know Batman will stop them.").
Ask a backbench MP or an assistant manager at PC World. Yesterday's henchman is tomorrow's baddie; the last episode of Boardwalk Empire I watched featured Al Capone, Meyer Lansky and Lucky Luciano as no-mark underlings plotting to make their move on the much smarter and more capable kingpins they serve.
Obviously Julie Newmar's Catwoman in the sixties Batman TV show would have had less trouble recruiting than other villains.
HaHa! Where indeed?
Well, you have got a few different examples there. Firstly The Penguin - I can see why someone would be a goon for him. He is generally portrayed as being sane and basically involved in organised crime so the perks for a goon there is money and power, much like criminals joing the mafia and such. Also, he generally treats them well from what I recall.
Now the Joker - why would anyone be his goon? Beats me, that guy is CRAZY. He is just as likely to kill a goon than someone else. Often there is the threat factor i.e. do something for me or I will kill you but other than that, you would run a mile. A think a lot of Jokers goons have also come from Arkham, so they are a little crazy themselves.
The job center sends them to work for various baddies or they'll get their benefits cut off, criminals of course only coming from the lower-income classes. Henchmen have literally no choice but to work for "private businessmen," though there are likely the odd career criminals who think "sure, I'll punch Batman in the face for you," because the criminals who aren't poor are stupid.
ISTR quite a postmodern Marvel Comics story I heard about once where a superhero infiltrates a secret island base of a supervillain and discovers that it is a facility that clones henchmen.
Marvel's shades-of-grey villain/anti-hero Taskmaster historically trained a lot of the henchmen in the Marvel U at various 'criminal academies' - he was pretty much the in-universe explanation for these guys.
It's all very well having Baddie Henchman as a job title, but the goodies don't do so well sometimes either...
"You - yes you - in the red uniform and with no name. We need you to accompany Captain Kirk, Spock and myself to this alien planet.... No it's perfectly safe... Don't be a wuss...."