I am sure that Troll Tech put a lot of work into Qt.  If Qt were free
software, I would be very appreciative of this work.

Motif and Qt are a good comparison.  Both of them are useful if judged
solely by technical criteria, both are non-free, so both of them are
off limits for free operating systems.  That is why people are working
on free replacements for both Motif and Qt.

The free replacement for Motif is called LessTif; it took many years
to write, but it is working usefully now.  The free replacement for Qt
should take much less time, because a lot more work is going into it.
Perhaps that is because the free software community is bigger now.