I think you are playing a rhetorical game with the reference to the weathermen as a counter example because many members of the group are today successful and have high prestige positions.
The question is not did some level of participation in this group ruin the lives of all individuals involved in the group. The question is did the violence of the group lead to their aims to come closer to being achieved.
Yes, but do you think that the violence from Hamas has brought Palestinian independence, or the achievement of other Palestinian goals closer? Yudkowsky’s claim is not that saying nice things about Hamas will be a bad political/social move in the US. The claim is that the use of terrorism is worse than nonviolence at achieving political goals, and the failure of Hamas to achieve its goals seems to be an example of this being true.