Normally--and sadly, of course--you'd be right. But for a variety of what in hindsight seem to be fairly obvious reasons, it's turned out that these Downtown office-to-resi conversions have, unless I'm mistaken, required absolutely zero support in the manner you describe. Think about it:
1.) They're all renovations, and not new construction. Thus they are not altering the skyline, nor (warning: pearl clutching incoming) adding any of the dreaded net new shadow.
2.) Given their Financial District locales, how many of these have preexisting abutting residential complexes to raise a fuss, in the first place? I'd guess none, or not many.
Anyway, I just checked, and, the following 4 conversions have, by the usual Planning Dept. standards, absolutely blitzed through the development review process. Consider:
15 Court Sq.: 105 days
85 Devonshire: 51 days
129 Portland: 71 days
281 Franklin: 85 days
That's a 78-day development approval process average. Miraculous. Why can't they all be like that, obviously!
(P.S. note I didn't bother to check their comment letter archives, maybe some actually do have a stray cranky opposition letter, but I'd be surprised if that was the case!)