Well the reason I keep them is to learn as much as I can about their requirments in captivity so I can get more people to try and keep them. These animals are what I believe to be the next wave in the invert hobby, after all I dont remember centipedes and roaches being that popular 10 years ago so as you say they have quite the potential. They also have more personality than most inverts do as well, and can actually learn things over time, they are smart for insects. And lastly its fun and rewarding to educate people about them, especially when they find out you can keep them as pets with little chance of them stinging you.
Also the solitary wasps are another great avenue that has yet to be explored, and some like the tarantula hawks are impressive. I will be trying to keep some solitary wasps this year.
On a side note it may b ecoem nessesary for conservationists to keep certain species as they are threatened with habit loss and climate change, and having a basic framework down will greatly assist their efforts.