Yes, early 90's were a tough time, but not tougher than Clive Rush years...after Berry got fired he wasn't replaced with anybody comparable; several veterans were lost to retirement and also not replaced; and front office and ownership were in turmoil--but not as bad as Celtics' in the late 70's.
That whole time - three seasons - spanned twenty-eight months. Green Bay's status as the Siberia of the NFL lasted twelve years, until Lombardi arrived. After he left, they were lousy for decades.
As for Orthwein, once the league sent him here-with the sole intention of moving to St. Louis-he did follow the standard, generic American cookie cutter formula for a struggling product: First, make sure it's nothing you're personally attached to or have any affinity for; Second, totally buy into any and all baseless criticism especially from those who are mortal enemies of said product; After five minutes here slap something inferior to predecessors together and totally rebrand the name-quickly in this case, so you create an excuse not to ask the Super Bowl-winning coach you just hired or anyone else who knows anything about football or the Patriots their opinion; And proclaim your product New, Improved, Better, Different, all the things that get people's attention.
So you sell out the stadium because of the coach; and people with money buy merchandise with the new branding on it because they have money and will buy whatever is sold by the local professional football team, often for their kids. This is the demographic that matters to ownership, NOT longtime/lifelong supporters from the beginning-because long-term faith and loyalty mean nothing and, according to the marketing experts you're paying a ton to, they do not translate into profits.
There's nothing wrong with Glenn, Slade, Law, Bruschi, Coates et al. and it's certainly not fans' fault, but the Celtics climbed right back to the top without trashing their look and heritage-because people who actually cared about the team were in charge.