I thought the sarcasm was modestly successful. :)
I don't agree with your take on this. Number one, as fans, Arte Moreno's financial interests don't have to be ours. You can make the argument that these interests form the bounds of what is possible, but that doesn't mean posters on a fan forum have to internalize this perspective. (I mean, if I just want to engage with the management point of view, I'll go to the Angels' mlb.com website.)
Number two, the need for a potential clean slate really would depend on the owner and on the manager's contract.
If you are signing a Terry Francona (or even a Don Mattingly (yikes)) to a 5-year deal, then yes, that contract could theoretically be somewhat of a very limited albatross. I say limited, because, as best as I can tell, the manager's salary doesn't count against the luxury tax. If you get a relatively deep-pocketed ownership group, then a 3-year contract, for example, is a relative drop in the bucket to them (which is why it is not uncommon for managers and GMs get fired well before their contract is supposed to end). If you hire a less experienced manager, though— or sign Phil Nevin to a multiyear contract— then the money outlay is even more negligible, relatively speaking.
If we get a new owner who finds eating 2 years of a manager's salary is too much of a financial burden, then there's going to be a lot worse long-term problems for the organization than making a single unsuitable managerial hire for this year. And when you look at the Angels' financial upside, I would be very surprised if they did not have an owner with deep pockets.
So that brings us to the Nevin hire. What do we know about him? We have a body of work with this team. And he was 14 games under .500 after he took over a more or less .500 team with more than half the season to go. Yes, there were injuries (which there were under Maddon, as another poster pointed out), and the issues for this team did start under Maddon. However, the Nevin-managed Angels looked like an Angels team of the dark days of the 90's-- rudderless, lacking heart, not resilient. And say what you will about Joe Maddon, but the team played for him, in terms of effort. The team seemed to have an identity. Now, maybe it was a failed one, but Nevin was a whole other level worse.
Instead, the Angels should have found somebody else to manage-- even somebody with no prior managerial experience-- because, at least in that scenario, you don't know that you're getting a manager who won't lead you to the promised land. (Though, to be clear, I am not expecting a trip to the promised land next year-- just would like to think they have a puncher's shot of getting to the postseason.)