What on earth do you think “as infrequently as possible” means? It means cutting the number of shopping trips down to the absolute minimum needed for survival
But it doesn't and pushing those extremes is what's failing. Absolute minimum for survival (as stated by a pp) is about 3 weeks after your food totally and utterly ran out.
That's survivial and I think we'd all agree that's taking it too far. So, if we cannot say the absolute minimum for survival then we have to accept it will be more frequent than absolutely necessary.
If we mandate how frequently then people will suffer; once a week will be too often for some and not enough for others.
So we're left with allowing people to make thier own decisions, based on their lifestyes. The reality of that is that people will make different decisions to you and me. That's just the way of it.
I bet I could look at the decisions you are making across your life and find 100 things I consider to be immoral. You could do the same to me. As someone else posted above, just using technology automatically means that, at some point, you have placed your own wants above someone else's safety. An inconvenient truth most people ignore (including me and presumably that pp) because they want the tech.
The same is true in the shopping situation. Yes, some people will go to a shop more often that I think is necessary. Some will go less frequently than me. There is always someone who will think your own decisions are wrong - to scrutinise others is to invite scrutiny yourself and it is a certainty of life that you won't pass that test. No one can.