If all you do is count Federal Income tax then yes, you can say that yes it is relatively low (even though it was raised in 1993 and lowered somewhat in the early 2000s). But the fact remains that our overall tax burden is not "as light as a feather."
To put it more simply, I could say that if I was only counting state sales taxes, then a state like Delaware would have the lowest tax burden because it has no sales tax. But Delaware of course has other taxes that people have to pay. It would be just as wrong for me to say that Delaware has a low tax burden by just counting the (lack of a) state sales tax as it is for you to say that Federal Income tax is "low" when you don't add in all the other taxes we have to pay.