Only place I can recall ever seeing it as dwarfs, except when talking about people like 4'10 and under... for me, it's like calling Elves "elfs," calves "calfs," knives "knifes," etc. Just because something is traditional, doesn't mean it's correct. We've moved away from things like slavery, too lol
But hey, I can just change it for myself with URM. Whatever. None of the race names are capitalized, either. There's also other minor grammar issues, but for whatever reason, that one bugs me the most.