The trade nobody escapes
A filter makes 2 kinds of mistake, and tightening it converts one into the other. Strict settings stop ordinary questions; loose settings let through what the service will answer for. Choosing means deciding which mistake you would rather make, and no amount of engineering removes the choice.
Arguments about filters are usually arguments about where the line sits, dressed up as arguments about whether a line should exist. The line exists in every service; the interesting question is who pays for its position.
On this page
The 2 mistakes
A false stop refuses something that was fine. A miss allows something that was not. Any single setting produces both in some ratio, and moving the setting changes the ratio rather than removing either. This is a property of scoring rather than a weakness of a particular product.
The costs land on different people
A false stop costs the person asking: time, and sometimes the answer they needed. A miss costs the operator: exposure, a story, a regulator. Since the operator chooses the setting and pays for only one of the 2 costs, the incentive points towards strictness, and most services follow it.
Why strictness accumulates
Each incident produces a tightening, and nothing produces a loosening, because a false stop generates no incident. The line therefore moves in one direction over time on most services. This ratchet, rather than any single decision, is why assistants feel more cautious each year.
What a different answer looks like
Naming the few things that are refused, refusing those without exception, and leaving everything else alone. That trades a higher rate of misses on the operator's side for a much lower rate of false stops on yours. It is a defensible position and it is not a free position, and a service taking it should say so plainly rather than promising that nothing is refused.
Before you type
Could a perfect filter avoid both mistakes?
Not while the input is text and the question is about intent. Better scoring shifts the curve; it does not remove the trade.
Is a loose filter irresponsible?
It depends entirely on what stays refused. A short list held absolutely is a different thing from no list at all.
Why do services rarely publish the trade?
Because stating it means admitting that some misses are expected. Silence is cheaper, and it leaves people guessing why an ordinary question was stopped.
See the short list of what is refused, and what is left alone.
Open no filter chat