Humans have other senses besides sight you know? Taste, touch, smell and sound are all heavily involved in sex. And if you can sense them, you can imagine them. Do you need to see your partner to get aroused?
(Also, a majority of blind people have not always been blind, so I imagine many of them still also imagine what someone looks like)
I reject that kind of black and white thinking. We don’t have to classify people as either “cool” or “uncool”, or “good” and “bad”. We can criticize one thing someone does, while also praising something else that they do.