I personally prefer wxWigets over Qt, but I'm a user of both.
So maybe it is worth another look.
However even OWL and VCL were better than MFC. :)
They are the only viable alternative to WPF/Win32 on medical devices, automotive infotainment systems, factory automation dashboards, MCUs displays, ticketing machines,...
I bet that whatever KDE decides to do it will hardly affect Qt's profits.
First they have to make KDevelop match QtCreator, 3D Studio and Design Studio, then we'll see.
That is a big threat to the bottom line of Trolltech.
While Blackberry, Nokia and so on contributed a lot of money, KDE contributed a lot of the product and to the technical system. That poses a unique threat of replacement.
To think that such tiny contributions would scale up to replace what Qt offers today, including supporting devices that require NDAs is utopian.
The way to make money in open source is to sell service attached to software, software development as QT does it where services is small component is just not generating enough money. That's why RedHat is owned by IBM and Canonical Ltd. has revenue only 2x of Qt despite large number of users.