This also happens pretty commonly. However, it's not even unreasonable! Sometimes you write a paper and you don't do a good enough of a job putting in the context of your own related work.
And sometimes the reviewer didn't read carefully and doesn't understand what you're doing.
I once wrote a paper along the lines of "look we can do X blazingly fast, which (among other things) lets us put it inside a loop and do it millions of times to do Y." A reviewer responded with "I don't understand what the point of doing X fast is if you're just going to put it in a loop and make it slow again." He also asked us to run simulations to compare our method to another paper which was doing an unrelated thing Z. The editor agreed that we could ignore his comments.
