These were almost certainly family members, not strangers. Obviously you would care after your child/father/grandmother if they were infirm regardless of economic system. And even that is far from universal. Indigenous Amazon societies still practice infanticide[1] in times of scarcity or for infants that are infirm.

[1] https://www.scielo.br/j/csp/a/kPn9cHW4RWKz94CjxDBw3ds/?forma...

>what care was available

This phrase is doing so much heavy lifting as to actively mislead people (i.e. lie with plausible deniability).

Take a subsistence farming community for example. If there aren't enough calories in the stockpile to feed everyone over the winter deficit they're gonna realize this in the fall and the less productive people will get their food rationed first and hardest and odds are some of the old (so like 50s) or otherwise infirm people who are in this huge calorie deficit are gonna keel over from a minor cold or something during the winter. The calorie math is what is and no amount of "well they cared for the elderly when times were good" misdirection is going to change the raw math of how frequently times were bad and the number of elderly, infirm, etc, that a society routinely subject to those sorts of "purge lite" events is going to be carrying at any one time.