If it is technical board, any useful answer will be bombarded with merits.
IMO it's just some useful answer on technical board which get merit. Besides, if your answer turns out to be unhelpful, useless or harmful, you could face major critic or even accusation.
I'm not sure why merit sources even think about ignoring a board like trading discussion. If I was a merit source, I would never ignore boards like trading discussion since it's highly helpful for Bitcoin community because most crypto users start their crypto journey with trading and if such board isn't given priority then that's not going to be helpful for those users.
IIRC theymos never prohibit merit source from ignoring certain boards, so it's not surprising some of them does that. Besides, some merit source who apply to be one mention which board they'll pay attention to.