I am talking about buying x times as much as you usually do when you go grocery shopping to build up a stockpile, including a larger supply of food that you can store for a long period of time (canned/frozen/dry goods).

Edit: And yes, it doesn't include everyone's homes. In particular it doesn't include the homes of people who didn't do this. Unless the store is literally bare it does still help those people though, because it means there are less people in the store who might transmit the virus to them.

How? What has it done to "more than inconvenience" them? Specifically what has it done to them except possibly cause them to have to buy different food today because they got a bit unlucky and the store is currently running low on what they normally eat?

On the flip side it means that when they go shopping in the future, when lots of people are sick, there will be less people at the store. This reduces their chance of infection. Do you really think the inconvenience today outweighs that benefit, even if we just look at them in isolation instead of looking at the cost/reward to society as a whole?