Progressive income taxes are here to stay since they provide the most efficient use of tax collection. Unlike flat taxes which hurt the poor and middle-class disproportionately, progressive taxes don't penalize any one demographic. If you're in a wealthier bracket, you're still making more money than someone else in a smaller bracket. Income taxes - unlike corporate and payroll taxes - don't impact economic growth much outside of spending.
Unfortunately, credits, deductions, and exemptions just destroy this purpose. The income tax brackets should effectively be reduced and expanded. By that I mean all current rates could probably be reduced by half and additional brackets could be made for those earning over $1 million and $5 million a year.
But no credits for having kids. No personal exemption. No mortgage-interest deduction or school tuition deduction. No "head of household" or "married" brackets, either. Tax people as individuals.
Let people see what they're actually paying.