I think there are pros and cons to getting to know someone anonymously.
I think an advantage to meeting someone online without knowing what they look like eases your anxiety. You wont have to worry about your looks or feel insecure about the comparison between who your talking to. You can gradually have a decent conversation and talk about mutual interest, hobbies, and such. It can also provide an escape when, you need to get away from reality. In time, you may find that you enjoy them for themselves, and your feelings may outweigh other reservations you may have. However, this is only possible if, your really getting to know someone and you are both sincere in your relationship.
A disadvantage to "no photos" lies in the same factor with meeting anyone online. There is no way of knowing if, the person your talking to is sincere. In fact, its easy to give false information about yourself, and perpetuate the lie for years, if you've never actually met in person. Their are scam artist yes but, their are also people who feel insecure about themselves so, they fabricate something for fear of the relationship ending.
People change in online as well, so you may never meet them but, you get to see a side of them through chat. If your happy remaining anonymous then, I think their is reward in that but, if you want something more indept and serious then, you will eventually have meet each other.