The idea that 'don't feed the trolls, you won't change their mind anyway' misses the point on several levels.
First, as Suddenly pointed out, many are just not trolls. They're advancing a movement in many cases.
Second, as many have noted, you don't have to feed trolls for them to keep going.
However the most important point I'd argue is that changing their minds isn't even a primary goal of engaging trolls and people who seem to be trolls. That is an absolutely false metric. It is the same false conclusion people get from various studies about how evidence doesn't 'change people's minds'. If it even just deters them from posting in every space because they don't want to deal with backlash, that's good. Better, more likely, and a good in and of itself is keeping minds. The lurker might be on the fence and seeing that a given idea does indeed have opposition works for the true as well as the false. Bringing people to your side, hopefully the evidenced side, is a win. Keeping people from embracing the false side is a win. Keeping people who are already on your side from being discouraged and starting to think it isn't worth the personal social cost it is a win. Just making them feel like they aren't alone is a win. Some get exhausted, and keeping them is worth it.
I agree with the concerns about spreading anti-reality ideas by addressing them, but that just requires a change of tactics, not abandonment.