Surely that was and will be the case for all other ico tokens as well. The representativeness of your comprehensive study is rather low. Look, there is currently no alternative valuation. So be happy if valuations go up and dont give a shit if they go down, thats what I do. Take it easy, be positive and have a drink. Long live Tezos.
PS: bancor is based on Ethereum, you might have noticed that Tezos will be the next level should it ever fly. Its a different animal and not comparable in any way to Bancor. Many might flip should the first trading day come, but fuck them.