I don' think it's a bad gamble, it'll just take longer then expected to lease all of this. IMHO, I think the Boston "tech hub" has pivoted in the last 20 years to biotech/life sciences. Kendall in particular seems to have more and more biotech, multiple new buildings around the Science Museum and Assembly Sq. Even Rt 128 "the computer commute" is ... well is far less techy these days (no more DEC, Prime). Who are the big s/w companies still based in Boston? EMC, Akamai? ...?

My opinion is that the pivot is driven by non-competes [without a much needed CA style prohibition]. Long ago you needed expensive computer time or pricy tools to write software, but these days you don't need a VAX to write software or an expensive MSDN subscription provided by your employer. You can do it on your personal laptop at home with open source tools -- your employer's non-competes significantly stifle this sort of innovation. However, Biotech and life sciences needs expensive lab space, specialized plumbing and infrastructure and complex equipment -- you can't really cook up a new drug in your kitchen on the weekends as you might with some new software idea.

So I think there's still a ton of super-smart people coming out of the universities in the Boston area, but the software folks are being drawn elsewhere (Silicon Valley), whilst the biotech ones stay because of the inertia here.