I disagree. I think it's up to the individual to reveal themselves when they're ready and that guy should never be pushed to doing something he believes is uncomfortable. Their reasons for not revealing are numerous whether it's their job, family life, etc. Whatever the reasons are, I absolutely respect them and their choices.
I was speaking to a guy whom you described OP. The reason why he chose to be hidden is because of a high profile job. However, he unlocked his private photos for me where he had his face pics (no nudes) once he trusted me following our conversation. And what a beautiful man he is too! So overall it's their privacy. Their are tons of guys already on this site with their face showing so if a headless pic is chatting with you, ask for his pic and if he refuses to reveal, simply move on.