My brother is a Fireman/Paramedic and a JW. I think initially there was a bit of pressure on him from the Elders because, before you even start, you have to put in A LOT of time in training, education, etc. Also, when you start out your schedule will not make it easy to do the JW regiment. However, he has been doing it for over 20 years so he has more flexibility and has privileges.
Regardless, my impression has always been that religious organizations often have a very parasitic relationship with the rest of the world. They most definitely benefit from the hard work, sacrifice, brains, energy, and modernity while giving little to nothing back. The JWs probably being one of the most parasitic groups of all.