I think the reason the no "internal promotions" idea is so strong is due to the fact that no one has a bachelors degree thus you never see anyone get promoted. I mean - think about it? How many TMs at your store have a bachelors degree? Not a lesser degree like an associates or "some college", but an actual bachelors degree? I know at my store no one - no TM or TL - had a bachelors degree. Hell, I was the only one below ETL level that even had an associates degree. Also, remember that target does not accept online degrees like Devry or University of Phoenix, so that knocks a lot of people out right away.
Also - some TMs bull sh** about having a degree. For example, I interviewed a TM one time (that we hired). During the interview she was bragging to me that she had just gotten her GED and was so proud of herself. She actually brought the GED to show me, and sure enough she had just gotten it. (really you don't even need a GED to be a TM)
A few *months* later I overheard her bragging to other TMs that she had a four year degree.....
So moral of the story? If a person is working at target as a TM that is pretty much your first clue that they do not have a degree.