Pre-check is profiling, TSA-style.

'Profiling' usually means trying to identify the handful of 'bad-niks' in a population of innocent people (because the vast majority of people are innocent in this context). If you are identified as a 'bad-nik', you're probably facing additional scrutiny for life, because mistakes are never made and hey, once a 'bad-nik', always a 'bad-nik'.

'Profiling' TSA-style means trying to identify the handful of conditionally trust-worthy people (because TSA security functions on the assumption that the vast majority of people are guilty of something, even if it has nothing to do with aviation security). If you are identified as a 'good-nik', you're still only trusted until the next time, because mistakes are made all the time and hey, just because you're a 'good-nik' today, no guarantee you'll still be a 'good-nik' tomorrow.

The ugly thing about this is that TSA's approach is that everyone is guilty and deserving of extra scrutiny be default. TSA is trying to identify the trustworthy people on a case-by-case, flight-by-flight basis. That means the folks who aren't Pre-check qualified (or who are, but didn't get cleared for this particular flight) are even more suspicious than before - otherwise they would have been Pre-check cleared.