I suppose its easy to mock people buying loo roll on a footy forum, but its a knock on effect; today I've been around various shops buying essentials for my weekly slow cooking and almost every shop I have been to has been sold out of bog roll, or been left with the expensive varieties. I went to Makro and they were sold out of everything except the large blue varieties; the trouble here is do you say "I'm not going to panic buy, I'm just going to buy a 6 pack and restock when that is used up as per BAU" or do you consider the fact that everyone is panic buying, and by not buying a good amount you are going to run out? What are you going to do if you do run out? wipe your **** with towels?
The shortage is not cause by people thinking that we are going to run out of bog roll, incidentally - people saying this have not grasped the reality of the situation. As Millbrook said, people are trying to supply themselves with what they will need to hole themselves up for 2 weeks+ for self isolation for themselves and their family, likewise with food. You cant self isolate if you need to go to the shops to buy another pack of bog roll.
I don't think there are going to be food shortages and the like, but I've bought a few KG of brown rice, baked beans, tinned tomatoes, whole grain pasta, tuna etc so that if we do have to self isolate, we aren't having to pop to tesco in the middle of it to survive, which defeats the point of doing so.