^No disrespect but the benefit of all of them being towers would, obviously, have been more land available for more construction. Alewife is the Red Line terminus and a no-brainer for lots of density. The units underway now are a good start but only a start and Fresh Pond Mall is ripe for a total overhaul to accommodate the needs of many, many new residents (including housing above the stores and parking garages instead of surface parking lots.)
You're right about this and Cambridge is already planning to do it. The problem is that every plan I've seen for Alewife (and I work there, so I'm invested) makes references to "easy access to the Alewife Red Line Station" without actually noting that Alewife may be the least pedestrian accessible station in the MBTA.
First you have large scale access - getting there from where you are. If you happen to be along CambridgePark drive or toward Davis Square, great. Otherwise, you have a pretty impenetrable barrier between you and the station. The city plans have had a few bridges/tunnels in them to cross the RR tracks, but they're pretty pathetic - the western one would end in the parking garage of an office park and you'd have to go down it's stairwell to get out.
Then you have the station itself. It's fine from the Eastern approach, but from the parking garage side? There's 4 western entrances to Alewife. Three of them are dreary ramps which are so poorly designed that the station was flooded for weeks in February as melting snow flowed down them. Of those, one puts you in the bus station, one spits you out down the block from where you want to be, and the last one deposits you in the parking garage with driveways on all sides, crosswalk free! I'm serious - try it. Walk due West out of Alewife like you want to go to CP Drive and you'll find yourself on an inescapable island in a sea of traffic.
I realize that the parking garage fills up and that it serves a pretty important purpose for park-and-ride folks (which would be better filled by extending the Red Line to 128 to distribute the load, but...), but you can't build a proper transit oriented neighborhood around a station no one on foot can get to.
One solution might be stealing a sliver of the garage (replaced by adding levels to the structure elsewhere) and building a true retail concourse from the corner of CPD and the Access Road (GIVE THESE BETTER NAMES) out to Fresh Pond Parkway. Then, you could redevelop the plot across CPD and link it with a skybridge (which are typically bad but here allows for all the necessary turning lanes. Stick a real grocery store (not a WF or TJ), a Walgreens in there along with restaurants to serve all your new residents.
Like this (yellow = circulation, red = 3-5 story retail, pink = 1 story retail under parking, blue = parking garage):
Unlike the "shopping center" concept Cambridge has covering the current Fresh Pond Mall, you might actually take some cars OFF the road by building the retail as a part of the station, and the facadectomy on the parking garage would do wonders for the whole area.