While understanding that sentiment, I think it is to one-sided. I mean, apart from Fergie, how often does it happen, that somebody is going to stay for so long having so much success? Wenger won his first titles in his 2nd year at the Gunners. So all in all, I know, the Fergie story is one of the greatest in sports but how realistic is it to expect that the same thing happens again? And that the only deciding factor was in fact the time?
I also don't think that teams like Real Madrid, Barcelona or Bayern are soulless husks. It feels like you try to construct a world, where we can "do the right thing" and remain with our soul intact plus successful. Doesn't feel realistic to me at all. Again, the results have been really good and I am not for sacking him just to get rid because he is "soooo bad" but for me, it needs to be noted that he didn't show too many indicators that he can be one of the great managers. He did a very good job recruiting and creating an atmosphere, but I think, it is at least debatable if these are the most important aspects for being a manager these days. Because who knows, if your Fergie story would even be applicable these days.