Make everyone write a check.Your answer to the problem as you have defined it is what?
I would actually prefer this method but your argument is fallacious.
IF your OP is correct and making a business collect income tax is forced servitude, so is forcing me to write the check. TO claim that requiring payroll to be parsed out before it hits the employee through regulation is forced servitude is one hell of a stretch of logic. You are not performing anything for the government; you are paying the taxes that you owe on payroll.
The practice is dishonest and deceiving because the employee never sees what they actually cost the company but it is not slavery or unconstitutional.