Why doesn't Blizzard embrace the desire for Classic+ in WoW?

This has always kind of been a curious topic for me. Ever since Classic launched in WoW, people have been requesting Blizzard to consider some form of 'Classic+' experience. This would likely entail an expansion-less model based on Classic WoW, with updates being added as they are polled by the playerbase. I know they have done minor tweaks in the Anniversary edition and SoD, but a 'true' Classic+ has never really been mentioned by Blizzard. OSRS as we all know has been a massive success for Jagex. Why do you think that Blizzard refuses to acknowledge the desire for a similar model in WoW?