I honestly think the difference is the fanbase. As a fan of both series I think ASOIAF/GOT fans, while they dislike a lot of things D&D did and are valid with their criticism, they are more accepting if the show is good. It doesn't matter if it breaks the book lore. There were some good things D&D did in the show that were better than what GRRM did in the books. A lot of Tolkien fans, and I hope I don't offend anyone here, come off as stuck up and can be a bit crass. GOT/HOTD is also more politic focused which is probably the biggest factor the series appeals to a huge audience & can capture those who do not like Fantasy like LOTR. HOTD/GOT is just more edgy and "realistic". The characters and Dragon action also appeal to a lot of the broad fanbase. GOT also had many more women characters people identified with more. At the end of the day I am enjoying both series and LOTR will always be my first love. But I think it just comes down to the fanbase and the demographic. It also doesn't help that we are in an era of YouTube incels with big platforms making content to purposely divide audiences.