As "bad" as 15%? Tax is at least 38% here in Au for that wage (was 60% not so long ago).
It is a myth that America is a low tax nation.
http://en.wikipedia.org/wiki/Government_spending#Government_...
In American those taxes provide a strong military. Most of the rest of the world are very poorly equipped by comparison. Other countries get health care and education.
The differences in tax between the US and Australia are not so much in the headline rates as in the deductions.
In the US mortgage interest on a home you live in is tax deductible.
And in the US you get taxed as an economic unit with your spouse and children.
So a home owner with a big mortgage and a spouse at home looking after kids pays much less tax in the US.