Interesting point of view.
I'm on exactly opposite end - I'm going deeper with ICO's this year.
Your points are pretty valid, but this mean you just need to be more peaky where you are investing. And I'm always and only buying during the pre-ico phase, avoiding those ICO's with massive pre-sale.
Of course, now in my own opinion I don't think that this is valid enough for me to quit on ICOs, there are ICOs that are reliable out there, you really just have to be picky on finding the ICO that will fit you and your standards, and I don't think that the ICO would adjust onto you, you will be the one that will have to adjust on making your investments, I hope that after what you have said and what the community has responded to you would make your mind up and go back to investing in ICOs.
ICO were good at one time but these days it is very hard to find a good ICO. May be one out of 100 ICO is good and rest are all scam or made with the purpose of collecting money and do not focus on any coin development.