This demonstrates what "ultra-Orthodox" Jews can do when they're really upset about something. So why aren't they doing this over "gay marriage" and similar issues? Once upon a time they actually did (back when homosexuality was universally condemned).
One reason for this quietism is of course that so-called "ultra-Orthodox" Jews are a very withdrawn group. They live in their own (quite literally Theocratic) world and are most concerned with getting along with whoever happens to be in power. In their world, these social issues don't yet exist (though the left wing of "Modern Orthodoxy" is pushing). The Israeli draft law impacts them directly.
Rabbi Yehuda Levin remarked in one of his videos that the religious Zionists in Israel (who come from Modern Orthodoxy) are more critical of the Israeli government than US "ultra-Orthodox" Jews of the US government.
Which is why (as I posted in #30) I think the REAL underlying objection to having their young men and women go into the IDF, is that they would spend three years outside that little world, bunking with non-orthodox, seeing non-orthodox of the opposite sex, and making friends and contacts outside their community.
This would make it a lot easier for an ultra-orthodox young man to leave the community if he decided he didn't want to live there any more, and would have friends who could make it easy to get established in non-orthodox Israel.