Evolution suggests that they do as they're told when they're young, as the warning usually comes from an elder who knows that crocs bite and fire burns. When they grow up they pass through a bolshy stage and refuse to follow advice: unfortunately some stay at that stage and refuse to listen on principle, like anti-vaxers or anti maxers...
when shops do it, it's called stocking up. When people do it, it's "panic buying". Given that shops did it badly back in March, you can't blame shoppers for not taking them at their word.
You can, jno.... it's the unexpected extra buying that shops weren't prepared for. Now, they have realised people are stupid and will buy more than they need, for no real reason, so they are responding to that.
pixie, it's not the public's job to buy only what they're told (unless they're still living in some forgotten corner of the Soviet Union), it's the shops' job to meet their needs. Unfortunately their just-in-time delivery programmes make it hard to do this; but it's the shops that need to adapt, not the public. In return, they do get to set their prices accordingly - remember how much sanitiser cost in March. That's capitalism for you.
The shops are adapting... but they seemed to credit the public with far more common sense than they had, in March.
The public will buy what they want.... but the panic buying in March, I doubt anyone would have predicted. It was needless. Why would you guess that people would overbuy toilet roll and pasta... when the shops were remaining open?
It's predicted now, anyway. They know how people behave and are responding to it. I don't honestly think buyers were rational enough to predict before.
Those that remain calm and responsible are at risk of inconvenience from those who panic. So if you want to avoid inconvenience what is the prevailing incentive encouraging you to do ?
They'll work that out regardless whether they're told what to do or not. Hardly the authorities' job to boss the citizens around anyway.