Sometimes it really is best to minimize the artistic license and let the masters work shine through.
In the former, you could argue your own creative vision might be "better" (in the loose sense), given the lack of popular success of the source.
In the later, it'd be a fair amount of hubris to assume you can make something more beloved than Tolkien's works.
Hubris, arragance, etc. You're coming back to words that mean the same thing. Just because it's a work you personally are not familiar does not make it more/less egregious that someone has taken the material in their own direction from the original. It's just that you have a personal connection to the orginal and may or may not like the reworked version.
That's why Amazon paid $$$$ for the rights.
It's unreasonable to ignore that and claim that taking the same amount of artistic license with Tolkien is the same as taking it with something else.
It is objectively different to adapt a more popular and well-known work.