"So why the need to clear shelves of pasta and bog roll?"
Perhaps it's the need to budget buy.
I've been stocking up. I can't afford to pay more for stuff, the shelves were clear of the cheaper alternatives. So I've got, toilet roll, sanitary wear, personal items, medicined, sauces, tinned goods, cat food, cleaning products and my alcohol and treats for Christmas. I've done my Christmas decoration shopping and wrapping paper ect. I plan on finishing Christmas, including my Christmas pjs (yes I'm one of them) asap.
I was on the shielding list (but didn't shield) and my aim in stocking up is to minimise my time in shops, as the infection rate rises. Shopping for me means a bus journey. Those of us who have stocked up will mean that's there's more for everyone else and less people in the shops.
@WankPuffins, my DD works in residential care and they've been told to stock up. She overseas four residential houses. They have been wared that activities will probably end and so service users will be at home more, coupled with staff absence and isolation, they need to get done what they can as soon as they can. Also community groups are getting ready for any shortages. Food banks, churches etc now know potential supply issues.
My Sister's Church (which she is very involved in) used to do Christmas dinner for 40 people, this year they are offering home delivery. The people being criticised aren't doing anything wrong and might be volunteers.