When the DVD was first introduced, some of the early discs were released in pan and scan 4:3 format. There was outrage from quite a few enthusiasts, who wanted to see movies in their original aspect ratios, a position with which I sympathise.
But, of course, DVD manufacturers had to make a guess as to which format would sell best, so I’m not and was never outraged about the choices they made. At least as far as that goes. Non-anamorphic letterboxed widescreen is a different matter, and should never ever be used for a DVD.
What I found interesting was a remark on an IMDB message board from a commenter called ‘aventer-1’. The commenter claims to have been a film projectionist back at the time that widescreen movies were being introduced into cinemas. From what he says, it seems that films were rarely ever shown the way the director intended. It’s well worth a read.