That's very academic. The GPS is available under GPL (see https://github.com/AdaCore/gps). As long as you don't deploy GPS or link your app with it you can use it for closed-source apps as you like; it's definitely no GPL violation.
> This sucked for Smalltalk
Not sure why you compare it to Smalltalk; but for the latter you can use Squeak for free (under MIT or Apache license) since the nineties and today even a couple of other powerful Smalltalk implementations such as Pharo.