They "disrupted" parliament within the bounds of the rules, that's why the speaker couldn't kick them out because they didn't break any rule. They simply used the right to raise a point of order to make frivolous points repeatedly, and there's no rule that prevents this ie, the raising of a point of order - it is only after the point of order is raise can you determine that it is frivolous but until then you don't know and so you cannot prevent the point of order being raised. Their conduct should be understood to be filibustering, which is a tactic used in other parts of the world - its part of politics.