You are saying that income tax in discouraging people to work, do you have any evidence of this?
"When workers’ earnings rise but their after-tax income rises less—because of increases in their income and payroll taxes or declines in their benefits from government programs—their incentive to work typically declines"
Otherwise, it's just trivially true for any taxation regime: a flat 1% tax means your after-tax income rises less than your pre-tax income.