Is there a point...

[TinkerBelle2992]

... to all those backround thingys in the back of MGM. You know, those big walls with buildings on them, or are they just there to take up space??

 

[Robo]

It simulates a studio "back lot" city "set".

Many studios have/had them so they could shoot in (what looked to be) a city area without the REAL city PROBLEMS.

It is much cheaper for a film company to build only the fronts of buildings... as the INSIDE scenes where shot on a SOUND STAGE INTERIOR SET in another part of the studio at a different time.

DISNEY/MGM STUDIOS has a MOVIE-MAKER THEME, so this set is part of that theme.
(Besides, UNIVERSAL has one).

 

[Got Quattro?]

It is explained on the backlot tour as well. They talk about "forced perspective" and how set designers use it to trick viewers into seeing more than what meets the eye.