Why do you assume all ICOs are scams? Actually mining launches can be scams too.
We've been having a discussion about this over in another thread:
https://bitcointalksearch.org/topic/m.12136597
My opinion on developer anonymity is that it is very difficult to make a successful altcoin when the personalities of the core devs are unknown. However, jl777 has been quite successful at raising capital and talking very, very little. How did he do it? Apparently by delivering code fast.
I am not attesting to the quality of his code or designs. I will remain agnostic on that. I am just pointing out that anonymity can work if you are not a bullshitter and actually deliver the goods.