I consider memes informal communication.
If you want to fight against the contraction "alot," that's fine with me. It doesn't look right. I don't like it personally, and I wouldn't put it in my memes.
But I don't think it's right to correct someone else when they use a common informal contraction in a meme, that's all. As far as I know, "alright" used to be two words, too.