If 1 in a million people will go on a killing spree, when driven to rock bottom, then you would expect to have a few, if you drive millions of people to that position.

Victorian England introduced various social safety nets not primarily out of goodness, but out of cost. It was actually cheaper to just feed the starving, rather than stopping them stealing for food, and punishing them afterwards. The fact it improved the lives of the downtrodden was just a convenient positive.

I think this post intends to convey that society has done those people dirty too and that we shouldn't wait until those "millions of people who are in...this same situation" turn into shooters before doing something.

Assigning blame does nothing. It'd be great if potential murders would stop and think "hey maybe murder is wrong. Maybe other people have solver similar problems without murdering anyone!" But that's not going to happen.

And yet those ppl are now dead. So advocating for any position other than the one which removes the possibility of people making the choice to kill others is to support those deaths. Which is to say to support the status quo in the USA is to support the deaths of these people.