Has Batman ever tried employing his villains at Wayne Enterprise?
Mr. Freeze, Poison Ivy, Scarecrow, etc. all have degrees and are experts in their fields. Has Bruce ever tried hiring these people to work at Wayne Enterprise? You could give Poison Ivy money and resources to regrow the rainforest, or let Mr. Freeze continue to develop bio-medical tech. Heck, Man-Bat’s research could be useful in stopping the transmission of viruses from animals to people.