Probably becase it has to be somebody's "fault". First they scapegoated hospitality, but there is no correlation between areas where cases are rising and areas where hospitality is closed - so those who like to play the blame game (whcih definitely includes politicians) are now lookig for someone else to blame.
The fact that on a UK and international scale there is no correlation between restrictive measures and number of cases ought to be a pretty clear indicator that restrictions don't work - but the politicians, and a sizeable part of the population, seems unable, unwilling, or determined not to see this.