Meme is just an externalist view to sign, which means that meme is sign without its triadic nature. I.e., meme is a degenerate sign in which only its ability of being copied is remained.Other critics cite Kalevi's criticism as though it is meaningful. For example it appears on RationalWiki's farcical page about memes. I recently thought of a new way of explaining how weak this criticism is: a word also a type of sign without its triadic nature. A word is similarly a type of degenerate sign.
To recap, the "triadic" nature of signs refers to Charles Sanders Peirce's ideas. Here's a diagram:
Kalevi is arguing that memes are only the bottom left. However, the same can be said of words. We count "park", "play", 'bark", "chair", "left" and "right" as one word, not two - despite their multiple meanings and even more numerous interpretations. This would be a feeble criticism of the concept of "word". We should assign it no more weight when it comes to memes.