I would guess that the simpler Acrobat UI is based on the needs of the average computer user while InDesign and Illustrator are typically used by more sophisticated users (or at least we hope) with a graphic arts background. Acrobat comes in a variety of flavors including the free Reader. It's heavily used in non publishing environments (corporate, education, consumer, etc.) Imagine Grandma trying to manually specify placement on a page using X and Y coordinates.
If there was an advanced section under Acrobat for power users, that could be more useful