A discussion on Harry Sinden is probably thread-worthy in and of itself.
As coach, he was well respected by the players and fans. As GM, he was usually booed by the Garden faithful, but that started when he traded Phil Esposito, a trade that played a key role in Boston's rise in the late 1970's. I remember the era well; we all hated him as fans. But when we look back, we do see that he made a lot more good trades during his prime than bad ones.
Cherry vs Sinden was one of those polarizing moments. Cherry was a great coach, but he was starting to go off the deep end during the end of his time in Boston. He openly clashed with Sinden on just about everything, and took those clashes to both the media and the locker room. And any coach that bridged the gap between Bep Guidolin and Fred Creighton would appear to be first ballot HoF material.
Part of the problem with Sinden's legacy is that he hired and groomed Mike O'Connell, who turned out to be truly awful as GM. Ignore the revisionists among the Globe beat writers: that Thornton trade is one of the worst in league history, never mind Bruins history. Interestingly, the Secord-for-O'Connell trade, while not as bad as the 12 mentioned in the Stanley Cup for Chowder, turned into one that many Boston fans wanted to have back when the Bruins were going through a goal drought in the early-to-mid 1980's while Secord was putting up 213 goals for the Hawks.