This doesn't make sense. What additional revenue would the GPL provide for you? How would a copyleft license end up requiring additional support contracts? Your other comment lists a range of things Redhat offers in addition to support, but none of those things rely on the GPL.
Qt exists as a business today because of its use of the GPL - enterprise customers can't ship the free version of Qt with proprietary software when its statically linked (as are all? Qt programs on Windows). PyQt works the same way, its an independent business run on selling proprietary licenses to distribute derivative binaries without source in exchange for money.
For a lot of business denying their users software freedoms are a value add for them because of the power it gives them to demand payment. They will, in turn, pay back for GPL code to get that ability. If it enables the further development of free software, its probably a net win.
Qt programs on Windows are not statically linked, i have a bunch of them (including some commercial) and none link to Qt statically. Also Qt is licensed under LGPL, not GPL.
Qt used to be licensed under GPL but changed that to LGPL for version 4. Incidentally this was around when Qt switched its focus from QtWidgets to QtQuick.
Those are good questions. As I think about it more, in the early days, Microsoft stirred up a lot of fear around open source and the GPL specifically. It was viral, it would get you sued for copyright infringment (see: SCO), it would get you sued for patent infringement, it was terrible quality, hard to install, changes all the time, the project might be abandoned, etc., etc.
So yeah, maybe it wasn't so much GPL specifically (except that "viral" threat), but overall Microsoft reinforced a bunch of concerns associated with open source and Red Hat was able to address those concerns.
