They made Mark Zuckerberg into the monster he is too.

The trauma he had from not being funded by the VC companies in Boston made him unable to listen to anybody about absolutely anything -- even his lawyers when they tell him not to have an incriminating paper trail for all his irresponsible decisions.

Prior to AI, there's Stripe, Dropbox, etc, which have a large number of MIT alum powering them, not to mention all them that went to the west coast FAANG offices.

State noncompete law handling. Weather. Availability of massive funding opportunities.

Boston is doing just fine with biotech/pharma.