The IRS views failing to pay payroll taxes as a serious issue because a large portion of the payroll taxes are your employees' withholdings. Not paying your company's payroll taxes is tantamount to stealing your employees' money in the eyes of the IRS.
As a result, penalties for failing to pay your payroll taxes and filing your payroll tax returns on time are much more severe than other types of penalties. They can drastically multiply the amount you owe in a very short time.
If you are behind on paying payroll taxes for your company, the IRS is extremely aggressive pursuing collection of this type of tax. The penalties are serious if you are behind on your payroll taxes.