If everyone is so sure that a helmet and a flight suit is not required in a helicopter then why do you bother strapping in - you are clearly not going to crash/roll over/catch fire so it's a bit pointless. Do you wear seat belts in a car? do you buy the latest models with airbags/crash protection etc?
I have been in an R22 that rolled over, wearing civvy clothes, a headset and a 3 point harness - apart from banging my head, the smell of fuel was enough to make me wish I had been kitted out the same way as when I fly in the military.
It's no good looking cool in your shorts and T shirts when it all goes wrong - I can buy another flying suit/helmet/pair of gloves but not new skin/skull/fingers. Dress to survive!