Major studios have this attitude that Blu Ray's are more important and worthy of special features to the point a standard DVD might as well be sold in a used CD-Rom sleeve with the title of the movie written on it in Sharpee.
Disney is the worst offender of this. And ironically, it seemed to start with
The Muppets (2011)... unless they've been doing it before then and I just simply wasn't paying attention, but since then, their DVD releases of new movies are practically bare-bone, standard releases, while the Blu-ray releases are the ones with all the special features on them now.
It's just like with the waning days of VHS, some studios started having some form of a special or two at the end of the feature presentation (
Stuart Little had outtakes,
Doug's 1st Movie had FAQs being answered by Jim Jenkins and the staff at Jumbo Pictures), but if you REALLY wanted MORE special features, you had to get the DVD instead... it's the same story now, DVDs may have a really basic feature or two like outtakes, but if you really want the really good special features, you have to buy the Blu-ray instead.
The bigger problem here, like Sarge keeps pointing out, is that there's also this attitude and mentality among studios and certain people, like if you don't have Blu-ray, you're a big, fat, pathetic loser.