Ownership of Qt by Nokia extends beyond just trademark despite that claim. Copyright license agreements give a lot more control to Nokia and make the barrier to entry higher if not impossible for a number of contributors. What would be ideal is for Nokia to move Qt to a non-profit foundation and create a vendor neutral zone. Nokia relicensing Qt to LGPL was a good move.
GTK still has the advantage of having a good number of vendors participating in the development including some funded by Nokia itself.