You say “group think” like it's a bad thing. There's always wisdom in crowds. We have a mob mentality as an evolutionary advantage. You're also willing to believe that 3–4 people can make better judgement calls than 800 people. That's only possible if the board has information that's not public, and I don't think they do, or else they would have published it already.
And … it doesn't matter why there's such a wide consensus. Whether they care about their legacy, or earnings, or not upsetting their colleagues, doesn't matter. The board acted poorly, undoubtedly. Even if they had legitimate reasons to do what they did, that stopped mattering.
Apple and Microsoft even have the strongest financial results in their lifetime.
It's fair to say that what got MS and Apple to dominance may be different from what it takes to keep them there, but which part of that corporate timeline more closely resembles OpenAI?