There are never going to be economic pressures laid upon the Estate by Harper Collins as the Estate merely make use of the services owned by the publishing house, and the Estate are not beholden to them. Nor is the Estate in any way short of cash. Or ever likely to be!
And the difference between CT and anyone else is that he is an
editor, there to sift through the fragments and put them together with maybe a note or two along the way. He only issues what his father had intended to do more with had he had more time in this world.
Books based on films may be one thing - but to have them based on Tolkien's work smacks of one thing only - dumbing down in the name of profit. Who knows, maybe one day a Literary Executor will come along with a burning desire to build himself a Tolkfork in the Oxfordshire countryside and build up a collection of Ferraris. Until then, why should the Estate pander to the wishes of the film fans, when they've already had not only the films but already have some perfectly good books to read - though to be nasty, maybe they are a bit too difficult for them?
Anything outside of the canon simply is not authoritative, never has been, never will be. Which is why matters of canon regarding the texts we already have are still so hotly debated.