I was bored.
During the drive home I pinpointed exactly why the film was so dull to me and why I walked out after 50 minutes:
The employees who were interviewed never moved beyond those menial jobs (or, at the very least, most of them worked there for an uncomfortably long period of time). Therefore their lives seemed more like dull tragedies than something noteworthy to me.
And A LOT of the film centered around their lives.
The founder's story and the stuff about Elton John was interesting, partly because I had heard about Elton sightings at the Sunset location well into the '90s.
Something that the founder said sort of summed up his attitude toward the employees and why I have zero respect for those old losers (paraphrasing): "It's the Tom Sawyer thing: get someone else to paint the fence for you."
Oh, and they did.