But that's true of any tax. I don't think it is specific to progressive ones. To me, the fact that larger entities are better at avoiding paying part of their taxes is an additional argument to make them start at a higher rate.
A progressive tax increases the per-dollar incentive to find a loophole as the amount of money increases.
Furthermore, by taxing different businesses at different rates it creates just the sort of loopholes that such avoidance takes advantage of. (I.e. a large business will try to find a way to count as two smaller businesses)
