The problem isn't that lack of green space or that it's "tired", it's how it's situated within the context of downtown. You have Cobo to the south, a major border crossing to the north and the entrance/exit ramp to a freeway at the only major pedestrian crossing to the park. All conspire to make it less accessible while not generating any significant traffic to the park. If it was directly adjacent to the Ren Cen or some other significant generator of pedestrian traffic, we wouldn't be having this conversation.