When you reach a certain density of businesses on a given street, the street parking is less useful. Increasingly you can only rely on the space immediately in front of your business. And the 2-4 parking spaces in front of a restaurant aren't going to come anywhere near filling the place.

What would honestly help the businesses in that area a lot would be a frequent (say, every 15 min) shuttle that ran a small route from Kelley Square, up Water St, across Franklin St, stopping at the bus hub, and going down Green St back to Kelley Square. And have it run LATE. At least until midnight. Could stop waiting at the hub after the last commuter train leaves, since other buses all stop running before that.