Good question, Mike. I don't tend to give them a pass any more than some of the mediocrity I see in S. Boston. Most of these Back Bay towers were built at time when the city was desperate to fill in the hole created adjacent to Copley Sq. by the turnpike ramps. Personally, I hated the design of Copley Place. I don't like the idea of a retail center turning its back on the street scape. The blank wall of the Westin, the unrelenting boredom of the Marriott and the lack of imagination sheathing Copley Place offices/mall still depress me, when compared with the old S.S. Pierce building formally on the corner of Huntington Ave. 101 Huntington was an improvement, but it had little competition. It was supposed to be much taller, but S. End residents objected and it was cut in half. I think the taller version would have been even more interesting. The next-door Greenhouse Apts. look like cardboard cut-outs making the nearby buildings look positively inventive. The Trinity is smaller in scale, but I liked much more the old brick office building it replaced, especially being so close to the BPL.
The issue in the Back Bay for may, I believe, is the fact that there exists so much great and very good architecture, that a few mediocre towers do not detract from the area as much. The argument in S. Boston, as I understand it, is that there is a blank slate which runs the risk of being filled with boring architecture, since it is being developed over a relatively short period of time. We mustn't forget that the Back Bay was built over a fifty to sixty year period initially. The change in architectural tastes from Arlington St. to Bay State Rd. is remarkable. It remained moribund for decades until it continued developing from the period of the first Hancock and New England Life buildings through to the Pru phase of the sixties and the Christian Science Center and Copley Place phase that followed. Too bad in some ways that we're in such a hurry to get S. Boston developed (or maybe it will indeed take as long as the Back Bay!) The one thing I can say about the Back Bay is that all those towers look spectacular at night!