My supposition is that no one wants to hitch themselves to a self-defeating movement. In particular, MRM has not adopted any viewpoint that will solve its problems and worse, it has attached a parasite to itself.
When in the course of creating revolutionary change, you bring with you the ideas of those you claim are your enemies, you’re defeating yourself — and the parasite you have attached is their ideology, which lives on in you.
How does MRM fail?
When presented with an ideology like feminism — the idea that men are oppressive, and women need zero obligations to men, e.g. “equality” — you have several options:
The first two options give you unending internal conflict. If you favor men, the next generation will over-correct and favor women, and vice-versa. You will fight this until your society collapses.
If you pick the third option, you have some wiggle room. In this, men and women have complementary roles and cooperate in order to make things work. This reduces some “freedoms” but gives you an outcome other than perpetual enmity.
To adopt men win versus women win is to adopt the viewpoint of feminism. That means that no matter how many laws you change, your assumption is still the same, and you’ll end up in the same place.
I hope men’s rights activists (MRAs) have more sense than that.