Unlike the starting point, a regular glass door, which effectively always accurately displays its inventory, a screen layer, by nature, introduces the possibility of inaccurate data, an entirely dark door, etc. Hardware maintenance is no doubt important: having a bunch of inoperative doors, especially in a single location, can lead to customers having negative experiences. The advertising premise is more straightforward - show contextual ads to customers seconds before they make a purchase.

It seems like you just used a lot of words to explain the obvious thing everyone who encountered them experienced. It's on obvious step backwards from a glass door. The engineers had their work cut out for them to fix the ridiculous problem that the product created in the first place. Only for potential benefit of advertisers, and at the guaranteed detriment of consumers.