It honestly didn't seem all that insane to me, because Boston is crazier in nearly every dimension. The peninsula at least has 3-lane boulevards with a reasonable road hierarchy and traffic light timings. Boston has cowpaths branching off in every direction, controlled by stop signs that can literally back up for miles. The peninsula has block after block of Eichlers on 1/4 acre lots. Boston has mid-rise row-houses on landfill in the Back Bay, quickly trailing off to historic old houses on 1.5 acre lots 10 minutes outside of the city. The peninsula refuses to let you put in an in-law unit or cut down a redwood tree without going through an extensive permitting process. The Boston area might refuse to let you put in new window panes if you live in a historic house (my computer teacher lived in one from the 1730s, and it still had all the original glass - which back then was hand made and tended to flow like putty - because it was considered a historic property and she couldn't modify it). The peninsula is due for a natural disaster in the next 30 years. In Boston, as my wife puts it, every winter is a natural disaster. BART has a problem with homeless dudes and property crime. The Red Line has a problem with trains losing the 3rd rail and running 20 minutes late. Caltrain electrification is stuck in limbo. The Big Dig has ceiling tiles that fall down and kill people.

Of course, the flip side of this is that Boston hasn't grown since 1950, and is around the same size as its 1910 population. San Francisco will probably meet a similar fate when the tech boom peters out.