Shroomy
Adventurer
Sure. I think it's fair to say that DD is an add value product. It adds value to the Dungeon Tiles, and the Dungeon Tiles add value to it, and both of them together are stronger than either one without. But, the flip side is, if you're pointing out that the emperor has no clothes, the whole thing falls apart (meaning, maybe less metaphorically, if you buy DD without buying Dungeon Tiles, DD is less valuable...and, perhaps, if you buy Dungeon Tiles without DD, that Dungeon Tiles are less valuable, as the post about the Troll King indicates, though each undoubtedly has a value of their own, too).
It's a conditional positive (and a conditional negative). It's fair to point out that the use of Dungeon Tiles constrained DD, just as it's fair to point out that constraint showed by DD enhances the value of your dungeon tiles.
I was actually pointing out that the constraints of having to create encounter areas with Dungeon Tiles paid off creatively. Personally, the marketing synergy is less interesting to me, though I think that WoTC had a good idea with the Dungeon Delve/Dungeon Tiles synergy.