Chicken and egg. If you always make it a requirement to "have everything ready at once", you'll never get anywhere. No single policy or law is going to get it all done at once.

Same argument could be said about parking.

"Why do we need more parking at the commuter rail station? It's not fully most days already?"

You have to start somewhere and then work on the other pieces. The housing/zoning law is a start. I'm all for legislation/policy that makes the MBTA more effective across the network. Let's see it! Is there anything in the works now?