Believe it or not but there are Americans who relinquish their passport precisely because of this reason.
Patriotism is automatically assumed but we live in a globalised world.
Of course collecting taxes internationally is difficult, but anyone wealthy enough to meet the criteria will probably need to visit the US at some point.
The US exit tax is a tax on your worldwide assets. The tax applies to all property that you own on the date of renunciation
That, and that the US is a tax haven for the super rich, so they have no reason to leave.