I often upvote Lumifer's comments simply because they contain good content (while downvoting the ones that are pure snark). I strongly suspect that many other LW users vote similarly. That Lumifer's comments are often upvoted should not, therefore, be taken as an indication that people appreciate their tone (and I suspect that Lumifer's karma ratio--which is currently at 80%--is so low at least in part because of the tone he/she uses).

(On a somewhat related note: I have noticed a rather strange phenomenon occurring, where one of Lumifer's comments initially receives a large number of downvotes, sometimes falling all the way to -5, before a sudden surge of upvotes, usually a day or two later, brings it back up to around +4 or so. This is not the sort of pattern one would normally expect to see, and yet I have seen it happen multiple times, which leads me to think someone else may be gaming the system.)