Say gross profit was $100, IRS-allowed expenses were $10, IRS-not-allowed expenses were $50.
IRS would compute tax based on $100-10 = 90. If tax was 30%, $27 in tax.
Actual net profit was $100-10-50 = $40.
Less $27 in tax gives $13 to take home.
If the IRS had done it right, tax on the $40 * 30% = $12 and the take home would be $40-12 = $28.
So yeah, I agree with the total unfairness of this IRS interpretation.
I agree. And legal win high taxation is way better than illegal so I'll take that for now. Maybe it's not perfect but it's definitely going the right way.