People know what the risks are and/or some people suit it.
The risks are too great if not done right and/or they look ugly.
I love the aesthetic of eye tattoos and think they are a great cosmetic. However I personally would not get one due to the risks of going blind. Some people may find it worth it if they get it done to one eye at a time so that if they do lose their vision they don't go blind completely.
I think its risky, but in the future it might have a non-risky method thus it will be fine overall to do as I am pro transhumanism in any way shape or form.
Just use colored contacts.