TNG wasn't filmed in widescreen so it shouldn't be presented in widescreen.
So, as viewer sophistication grows to where everyone owns and watches widescreen TV, they will choose to ignore shows that don't match up with their equipment, or at least find that they just don't watch it as often.
I have several favourite LPs not available as CDs and, as much as I love them, they are simply too much trouble to play in LP format. Cleaning them with anti-static clothes, getting up halfway through to flip the disk, being careful with storage to avoid warping...
Just as people found themselves no longer playing mono records on their stereos, replacing beloved LPs with CD version, watching early b/w episodes of "Gilligan's Island" in syndication when the laters seasons were in colour, or buying colourized
"Bewitched" boxed DVD sets in preference to the b/w sets right beside them.
If Paramount aims DVD product only at the purists, they'll go under.