Personally I generally advise our developers to avoid using GPL-ed software, even as part of web services, as much as possible - only exception being Linux, which we use as a OS, but we are moving to BSD steadily.

Surprisingly (or perhaps not so surprisingly) there are excellent non-GPL open source alternatives today. And my subjective impression is that recent open source projects that use GPL are less popular than BSD/MIT/Apache based alternatives. That may be confirmation bias, of course.

So in that sense, I agree that GPL is declining ... frankly, I am happy with that development, because I don't consider GPL to be a license so much as a political philosophy, a philosophy I strongly disagree with. Which is why we choose not to use GPL software to the maximum extent possible (much as Stallman would choose not to use the software we create, which is perfectly fine with me!).