You're entirely free to like or dislike a piece of art based on it's [lack of] socially conscious undertones, and I definitely have a few which fit that bill. I do think, especially considering the impact of Tolkien's writing, that it's better (both for the diversity of artistic expression and personal opinion, and also for our own frame of mind) to not hold art up to a unitary expectation.

Certainly we can discuss the perspective of the author and the psuedo-effects of their pieces on our culture from that lense. It's not a discussion though when people claim an author is racist for not including a topic in their works (to the expectation of outsider critics) - even if by effect they arguably did worse for the issue on the whole. A proper discussion would be of the like in your comment and mine, but thats only possible because neither of us started with broad-sweeping conclusions that dismiss a man's character for our own prejudice, as you suggested.

For discussion purposes, I think there is a difference in authors who are direct or indirect in how they address issues. The assumption often is that the author who directly speaks to an issue(s) (through the immediate reactions and juxtapositions of characters) cares more, which usually is a reasonable assumption, to be fair.

But can we actually conclude that one affects the social issue more simply because it is more easily & consistently heard? Probably, in the case of Harry Potter.. but not always! The louder you talk about a real issue the more you're taking me away from the fantasy of fiction, which is why I believe LotR was effective for its time, because it had a delicate way about touching the subject.

Not to mention, in a fantasy as distant as medieval [New Zealand], compared to Harry Potter which is set in a modern, diversified era - it seems more natural for social issues to exist in one vs the other. In some fantasy race is an undertone because the world allows it to be - and by that experience we are given the comparative tools to see differences and similarities to our own world. In fact, I think one serious issue with our culture is that we really do believe issues to be 'black & white.' We have a hard time accepting anything other than perfect, which makes me believe it must not be all that perfect otherwise we'd have all been on board by now.