If you wrote the software you can do whatever you want with it, including releasing it under the GPL.
Nope. Gamedevs are covered under both non-disclosure and non-compete agreements. There's a lot of red tape to cut through to release something as open source. Even if you've written it at home on your own time, companies have made a big deal about employees open-sourcing code before.
This is doubly true in the finance industry.
Without MIT licensing, there would be an extra hurdle of "GPL? We cannot under any circumstances be associated with GPL." It's absolutely silly, but absolutely true. I'm speaking as someone with firsthand, I've-been-there-in-person-and-dealt-with-this experience.
Also, by releasing it as GPL, no other gamedevs can use it. We gamedevs like to release code that other gamedevs can use.
That doesn't sound like a GPL problem, it sounds like an industry problem. As a game developer I'd rather complain with the industry and try to follow an ethical path (i.e. freedom with GPL) rather than complain to those people who release their hard work for free under the GPL. I admire those people.
Some game developers have been able to contribute software using LGPL to get around the restrictions of both corporate legal departments and the confidentiality agreements you have to make with Sony, Microsoft and so on. Electronic Arts for example made a port of Webkit which can run Playstation and Xbox, which is a linkable library and includes no reference to third party API's.
Personally I choose a license relevant for the kind of software and what it will be used for. When that includes software I want people to be able to use in commercial software I use MIT. I'm still releasing hard work for free, I don't have your admiration, but people get to use it.
Facebook uses the PHP license for HHVM which is a very significant OSS contribution, and has very similar terms to MIT.
Like people said, that you have a non-disclosure agreement has nothing to do with the GPL. My point was that no matter what other things you do with the software, including using it for a commercial game, you can also release it as GPL.
Other gamedevs absolutely can use it. The only thing they can't do is include it in a shipping product. Light Table appears to be an IDE, and there is no problem using a GPL IDE for writing a commercial product any more than there is a problem compiling it with GCC.
Nope. Gamedevs are covered under both non-disclosure and non-compete agreements. There's a lot of red tape to cut through to release something as open source. Even if you've written it at home on your own time, companies have made a big deal about employees open-sourcing code before.
This is doubly true in the finance industry.
Without MIT licensing, there would be an extra hurdle of "GPL? We cannot under any circumstances be associated with GPL." It's absolutely silly, but absolutely true. I'm speaking as someone with firsthand, I've-been-there-in-person-and-dealt-with-this experience.
Also, by releasing it as GPL, no other gamedevs can use it. We gamedevs like to release code that other gamedevs can use.