Thing is, for RoP, they're dealing with a time period for which only a very bare-bones 'story', really more of a brief summary, was actually written by Tolkien. So actually it was not only possible, but even necessary, to come up with a lot of original plot, dialogue, characters. Very different situation from WoT which had way too much story for a TV show so inevitably writers would have to cut a lot, combine various characters, etc.

In some ways, the problem with RoP is that they did not dare to change enough - didn't dare to go with entirely new characters as protagonists as they should have done considering the setting, instead trying to shoehorn the handful of known characters into their story in ways that blatantly don't fit. I liked their female Elf protagonist well enough, unlike some people, but she's obviously not Galadriel so they should've had the guts to give her her own name and backstory. And while they did to some extent dare to come up with new plotlines in new locations, they still had to quickly tie them all to the handful of known characters, in ways which again don't make much sense.

So I think the particulars of the mistakes the writers made in the two cases are quite different - but yes, in both cases they are lacking in knowledge of and respect for the source material.