Go back to the dark ages? Why would you want to do that? Christ was before the dark ages so either way - long hair would still be shamefull in a man.
Also to say long hair is sexy may be the case in your eyes, but ti say it isnt shamefull is a contradiction to what God says.
You are taking the verse out of context. Dont worry, it happens often.
Paul was talking to the Corinthians about their hair length because it meant very different things than it did in our culture. The reason it was shameful for men to have long hair back then was because:
They were trying to look like women. It was shameful in their culture because there was to be a distinct look between the sexes.
Also if you believe so strongly about this then you have to take conciteration about the next verse. Are women with short hair dishonering God? Are they less spiritual and therefore sinning?
With that said, the rest of the chapter deals with head coverings. It was a sign of respect to cover your head while praying. Also being bareheaded or shaved was a symbol of being loose and unmoral in this culture.
Also if thats so true then why was Sampson's power from GOD was gone when Delilah shaved his long sinful locks?
Think about it.