85% of Americans should only have to return the postcard "this is what we think your situation is". The other 15% have something the government doesn't know and needs to file. The other 10% should have an accountant do their taxes and not software (which leaves a few% lost, not quite complex enough for an accountant, but not enough of them to support software for their situation).

Well, you could have done a variety of things that aren't reported. For instance, donating money/time/goods, winning from gambling/etc, inheriting money/property, winning things/money, face deprecation in assets like real estate, etc. Payroll and taxes have about a million edge cases and it's one of the reasons payroll is such a bloated industry.

I agree it's probably a bit much for most people though and not filing should be akin to not reporting anything else and the IRS should automatically calculate your return and mail a check or a bill if you owe.

There are too many additions to the tax code beyond that. Really, if they cut away 95% of the cruft then it could be dramatically simplified. Everybody has their thing they hold onto for dear life in a tax code.

Psychological warfare. A direct and personal reminder of our place.