[Principled]

... you can easily be in a situation where you pay no actual tax but pay thousands of dollars in costs.

That's my position too. So why can't I pay my income tax out of sales revenues? Or are you now saying I can, since my businesses are "small". Aren't small business the vast majority of our economy?

[justshutupandtakeit]

Income taxes of businesses are paid ONLY out of profits gross revenues are only one variable. You could pay zero income taxes with revenues of 10 billion or zero income taxes with revenues of 10 thousand. Or you could pay a Million on revenues of 4 million or a Thousand on revenues of a Billion.

"Small" businesses may be paying BIGGER income tazes than BIG businesses. You may have paid more than GM last year.
So forget "revenues."