I've got kinda mixed feelings on this one.
Regarding vending machines in general. I understand. I've had that problem opening the map as well. I came for a visit a wipe or two ago and opened the map and it was just god awful. BUT limiting what people can build has been addressed multiple times in the past and leadership is pretty opposed to it.
I do think there should be a light rule about it that if reported, an admin could condense the stores down and take out any extras in the instance of having multiple machines but not fully utilized. But if someone has 13 machines and they are being used to max capacity, that's just part of the game. Some people just enjoy running shops.
It's a slippery slope though. Just because you think something is useless to sell, does not mean it's useless to someone else.
I'm generally not a fan of limiting what people can do unless it falls under hindering other players, which this is, so I'm all for it.