People can debate this time after time after time after time. My take is this:
Singapore is a very business-centred place. Almost everybody here wants to become a professional, be it a doctor, lawyer, corporate executive, etc. In these professions, it has been utmost to be good at personal grooming, and that involves keeping short, neat hair for the guys, among other things. I don't know about others, but i've been to the US and Australia a couple of times, and never once have i seen any suit-wearing corporate executive sporting long, flowing locks. Those things, in our culture at least, are relegated to either the rockstars, the rebels or the gangsters. I'm sorry if i offended anyone here, but that's from what i see in our Singaporean culture today. I'm sure not many will argue against gangsters mainly sporting long or bizarre hairdos though. Anyway, the drive to these professions is school. Hence, if the schools don't start teaching personal grooming from young, when these people grow up and eventually do become professionals (assuming they attend school for this reason), will they be able to adjust to keeping short hair? Or will this argument, this time only pertaining to the workplace, crop up again? It could also be about discipline, though i'm not sure how it applies.
I'm sure many people will disagree, and even venture to call me a 'perfect example of the product that MOE schools want to churn out: the brainwashed, authority-following machine'. Let me clarify, i am not against long hair, but this is the reason i believe MOE and the government have for making a short, neat hairstyle compulsory. I like short hair, it keeps my head cool and reduces the need for styling (yes i am a lazy bastard).
Cheers all!