So this is an important terminology distinction. While you are entitled to your opinion not to house such fish with corals when giving advice it is important to make clear the difference, otherwise reef tanks would be relegated to a tiny set of boring fish that are “completely reef safe”. In reefkeeping “not reef compatible“ and “not reef safe” are terms of art, meaning a high likelihood to eat all or most types of corals, and sessile inverts. This term is generally used on facultative and obligate corallivores where a variety of corals make a substantial portion of their diet. Where as with “Reef safe with caution” Often shortened to just “with caution,” indicates a lower propensity for consumption of corals. This is typically assigned to fish that may or may not pick at corals, or only certain groups of corals may be at particular risk. Informed aquarists can mitigate the risk of “with caution” fish Through a variety of techniques, some outlined in the above Macna talk. You personally may be too risk averse with your corals for this course of action however you should not prescribe that onto others without caveat, as many aquarists find this risk tolerable.
Telling other aquarists what they will regret is pretty arrogant. I quite happily keep similarly, if not more, coral dangerous fish in my reef without regret. Just one click on my build thread would have shown that. There are plenty of highly experienced aquarists who keep these kinds of fish without regret. So please next time try to be informative instead of reductionist. You are entitled not to put this sort of fish in your reef, but not to saying anyone who does put these fish in a reef will regret it.
