Does anyone actually shop in Aldi

My wife and i normally get all our food shopping in Marks & Spencer and then top up with items they do not sell from Sainburys.

When chatting to friends and family they indicate a trip to others, for example Asda, Tesco or Morrisans - no one goes to Aldi and some have never heard of it either - so why is it the car park of my local Aldi is jam packed most of the time.