If MRAs were primarily motivated by actual concern for men's lot in life, they'd do more proactive work. Instead they are mostly reactive, coming out of the woodwork when something is mentioned about women. They bitch about how bad men have it in order to deflate the issue de jour, then are not to be seen until the next time someone talks about women.

The OP is utterly right in saying that the ground has been salted by these man-children. Men do face problems, but MRAs do little work and mostly just armchair whine. How many of them create working groups or petition politicians or similar? Compare to feminism, where while it has a share of whiners, is mostly pro-active; organising events, talking to stakeholders, starting discussions instead of derailing them. You see it here on HN, where a topic is about women, and the whiners come out to derail... yet these same MRAs don't post their own articles about men.