Would Tolkien have accepted the films?

[Legate of Amon Lanc]

I would second something of what Galin said, and I believe Tolkien's opinion would have even a bit deeper foundations. It isn't just about movie, it is about any attempt of visual arts - even drama! - to capture the story. A director, even if he was thousand times better than PJ, can only show you his portrayal of Middle-Earth - and that, in my book, is already something else than my Middle-Earth. The thing I dislike about blockbuster movies being made out of LotR is the fact that it imposes a certain image of the world on unaware and unprepared masses of people. For them, then, Legolas will forever be blonde skating thing with weird ears. Or even things which even picky fans could consider right - even a beautiful Rivendell scenery, let's say - are given simply one particular portrayal, and that is wrong, in my book. As for those who have been prepared, even they face the inevitable pressure of the author's depiction, and sometimes "some begin to attune their music to his rather than to the thought which they had at first".

Anyway, to quote the Professor himself:

Originally Posted by On Fairy-Stories

However good in themselves, illustrations do little
good to fairy-stories. The radical distinction between all art (including drama) that offers a visible presentation and true literature is that it imposes one visible form. Literature works from mind to mind and is thus more progenitive. It is at once more universal and more poignantly particular. If it speaks of bread or wine or stone or tree, it appeals to the whole of these things, to their ideas; yet each hearer will give to them a peculiar personal embodiment in his imagination. Should the story say “he ate bread,” the dramatic producer or painter can only show ”a piece of bread” according to his taste or fancy, but the hearer of the story will think of bread in general and picture it in some form of his own. If a story says “he climbed a hill and saw a river in the valley below,” the illustrator may catch, or nearly catch, his own vision of such a scene; but every hearer of the words will have his own picture, and it will be made out of all the hills and rivers and dales he has ever seen, but especially out of The Hill, The River, The Valley which were for him the first embodiment of the word.

Personally, I could say I don't (usually) mind illustrations - maybe it has something to do with that they are nothing "definite". I think a LotR cartoon is also not a big deal for me. But once it attempts to be too "realistic", I start vehemently disliking it. Maybe because fantasy should not be realistic in the way of depicting things by the means of "flesh and blood". But in general I share Tolkien's opinion above when it comes to the movies.