I'm impressed with how GW made great financial leaps. One can argue they stole from everywhere to forge their IP, but even those entities they stole from were stolen from older material, myths, folklore, etc. 40k is by far the more recognized IP of GW over fantasy and it's a really fun and entertaining IP and it practically sells itself if the leadership can get out of its way. In comes CEO Kevin Roundtree 5-6 years ago who turned the company around and has it on the rise.
https://techraptor.net/tabletop/opinions/games-workshop-2016-turnaroundAs for them being evil or not. I'd say they're an entity that wants to reap in profits so the big guys on the top, the investors, shareholders and such are happy, but also keeping staff employed, fostering growth so they can keep providing entertainment for years to come. They have to attract talents that has the desire to work for them producing top of the line product. People complaining of exploitation bore me, you can choose to work at GW or another employer down the street, you can choose to put your abilities on the line, start your own business and decide how much you are worth compared to your employees and set the pay to your standard if you're so bothered about it.
Go back to how this company started, the risks they took and the rough road they travelled to establish and popularize the IP and ask yourself how it could be done another way. If you have a solution, I'd like to see it.
We're in a niche hobby, so very few of us collect, model, paint and play with our little toys. I think if the hobby were a bit more mainstream the prices would push down because that would draw more people in, and result in crazy profits. If hypothetically GW discovers a way to provide automated quality prepainted models that was 60% Eavy Metal quality, it would likely bring in larger audiences that didn't want to bother with the hobby side. Maybe it drives prices down a little and grows the gaming pool.
Being a small hobby, it's expensive, as well as terribly time consuming. I'm barely able to find time to paint a dozen kill team models for some games planned this September. But that's a choice and considering how long its taking me to finish anything I really don't care about the price of a box or two of models. I buy them at the GW store, hoping it never closes because it's the only place I can go to play toy soldiers with strange strangers.