Who gives a shit about the skyline? There are plenty of massive projects in Boston - the Greenway, the Seaport - but they're urban planning-related, not architectural. And they're doing active harm to the city, not merely being insufficient.
The biggest problem with the greenway is that they refuse to let anything new and nice be built on it, (everything they backed has failed on its own, everything that COULD be built gets shot down, nothing but a 200 foot precast box allowed please!) so there are too many "dead zones" where there is no reason for people to stop or be drawn to that area of the park. The Seaport, well, what was there before? It's a whole new area of development, hampered by the FAA, and continues to show how messed up this city is when those large blocks keep being built no problem.
The skyline... well, this is like the first impression of the city. You see it well before you see the parks, or the seaport low/midrises, etc. I'm not on this site because I love the politics of it, or think we need more parks. I'm here because I love skyscrapers, and originally I saw all the projects and thought "wow Boston is going to look amazing in a few years!" Of course, all the big/semi-big ones are either canceled or delayed indefinitely. So, why are we holding up all these towers from 30-40 years ago on pedestals? As long as nothing is allowed to pass any of these and create new peaks, the city will continue to age from afar.
Here's some examples of cities getting great new towers...
Austin - the Austonian, 683 feet, almost completely finished, new tallest
Cincinnati - Queen City Square, 689 feet, outside basically done, new tallest
Calgary - The Bow, ~770, new tallest... EAP, 697, 3rd tallest
Mobile (Alabama!!!) - RSA Battlehouse Tower, built in 2007, 745', new tallest
Charlotte - Duke Energy Center, 764(+?), finishing up, new 2nd tallest
Oklahoma City - Devon Energy, 850'! U/C new tallest by 350'!
Philadelphia - Comcast Center, 975' 2008, new tallest
Let's go overseas a bit...
Perth, Australia - BHP Billiton Tower, UC, 768', new tallest
Brisbane, AU - Soleil, 797', Infinity Tower, 774', both UC, will be new 1/2
What about old historic cities?
London (I think we could argue that London has more history than Boston) - Heron Tower, finishing up, 650+ to roof, 750 to spire, new tallest in "the city"
also UC, The Shard, 1017', new tallest! The Pinnacle, 945', 2nd tallest after Shard!
Madrid - Just built 4 buildings in the 700-800' range
Moscow - Huge new business area, struggling with financing but incredibly ambitious with plenty of 1000'+ footers
Santiago, Chile - just built by far it's new tallest, Torre Titanium at 636(?) and currently building an even larger building, Costanera Center, 984' (300 meters = supertall)
I haven't even mentioned that about 15-20 Chinese cities are currently building 1000+ footers (check skyscrapercity for this one), or that even Vietnam is building huge (here's a real good one in Saigon
http://www.skyscrapercity.com/showthread.php?t=446673&page=34) I haven't mentioned the complete craziness of Dubai (terribly planned city) or other mideast counterparts, such as Doha, Abu Dhabi, or even Kuwait City (finishing up a 1350', I'm not kidding).
I guess I just want some of the excitement for my own. The city looks almost exactly like it did 20 years ago, and even 30 years ago would still be instantly recognizable today. So yeah, I do want Boston to build something bigger, so I'll have something new to point at one day and be excited about, instead of saying "you see that little guy peeking up over there? it's new". In 2050, when we are talking about the JHT as the "oldest reigning tallest of any major American city"... maybe then it will finally sink in.