The problem is that some people won't and aren't following guidelines.
A friend of mine has a nephew who was tested positive and had symptoms for about three days and all the family initially followed guidelines by all staying indoors. By the fourth day the nephew felt better so went back to school and as both parents didn't feel ill they too went back to work.
How many people have now been infected due to the actions of that one family is anyone,s guess. Location was not Rotherham if that,s any comfort.

This family have had a right rollicking from their next of kin but it's too late now.
A selfish, I'm fine, couldn't care less about others attitude