Some states in the US actually allow employers to pay below the award rate in the expectation that the difference will be made up in tips. Hence the reason it is expected in the US and has spread like a cancer to other parts of the world where the need does not exist.
In Australia there are minimum wage standards which includes loadings for holiday and sick pay as well as overtime and public holiday rates. There is no similar provision in the US.
This tipping nonsense needs to be properly understood. Like many others, I will not tip unless the service is something extra special (very rare) and I have traveled extensively in Europe where I only occassionaly tipped. Tipped more often in Thailand and Cambodia where there was a willingness to provide good service