As a DM,I take a lot of time inventing unique campaign-specific themed items for the PCs to find (if they're able to wrest them from the Opposition), and I'll be goddamned if I'll nuke my own work via Mordenkainen's Disjunction, just as I wouldn't make a painting for others to view and then set it on fire.
As a player, MD would make me cry.
Mordenkainen's Disjunction belongs only in the spellbook of Mordenkainen, as a curiosity of the wizard's Art.