All of my friends are girls and about 75% of them think I'm stupid for dying my hair randomly all the time. I've done colors from pink, purple, green, blue, blond, red, black, all sorts of different shades of different colors I could go for awhile. What's do you think is wrong with that? Girls get all sorts of things to have fun with from nails, clothes, hair, makeup, etc.. all guys get is clothes (barely)..
I do my hair all the time. I admit some girls think it's stupid and don't like it, But those girls already have their own vision of beauty in a guy and if that hair colour isn't up to their standard, That guy is screwed and not in a good way.
Well maybe you don't have the right face/hairstyle to go with the bold colours you're choosing, aha. Not to mention the amount of damage you're doing to your hair by getting it dyed so much. I think girls would receive just as much flak if they randomly changed to colours that don't suit them or look stupid.