Because blind people use software that reads the text of a webpage out to them audibly (or less commonly, through an RBD) but it can’t read the text in an image, because it’s not really “text” at all-- It’s just pixels. So it’ll just be like “uhh and there’s a picture here, that’s all I know.”
So blind people would not be able to enjoy the meme, which tbh is mostly text-based anyway.