Way back when I was a child people would leave their beetroot to grow huge - yes they were a bit woody, but given that the only thing people ever did with them was to boil them to death and then slice and put them in a jar with malt vinegar, what did it matter? They were going to be horrid anyway 
No wonder beetroot went out of fashion!
But more recently people have realised that small and tender is the way to go with a lot of root veg, and what a transformation - beetroot is now a 'fashionable vegetable' 
But I bet there are still gardeners and allotment holders out there growing beetroot in the way their fathers and their fathers before them did 