Touché.
I don’t think we are bad at detecting trolling. I think we are reluctant to act on it. There’s lots of regular posters who I believe do this. From newbies it’s easy to see, but I’m not sure you or I want to go down the path where the moderation is much more heavy handed. Because that’s what it would take - we’d need to intercede more often, in more edge cases, and we’d get some wrong too.
The positive impact of interceding more are a board with less crap to deal with. The negative impact is that posters that may add value will get caught in that net and we’d lose them.
I don’t want to lose people and ignoring crap is trivially easy. As a result it seems the optimal choice is to err on the side of caution and exercise forbearance. The ones who have no redeeming value too the board make themselves apparent in time.