I guess all I'm trying to say is that I think you should take people at their word until it is impossible to no longer do so.
The owner in question gave a reason for their departure--money concerns. I don't even think it's necessary to give a reason for leaving, but at least the owner did that. He also offered to stay another year if the team won the WS, presumably in response to raised eyebrows.
Suppose that he had started his other draft one season earlier, and had an owner quit, or that the team he is leaving is good for one more season. If he quit due to the same reason (money concerns) in either of those scenarios, I strongly doubt that any eyebrows would have been raised, or that the situation would have been posted here. I think he should be believed, and see it as an unfortunate occurence, rather than an owner being an *******.
Like it or not, prog teams go in cycles--they are good for awhile, and then they suck for awhile. Trading picks for talent is common, and often necessary when trying to win. I just replaced an owner who had traded his next 1st rounder away when he left... his reason for leaving was diminishing interest, which I fully believe. He did a great job during his seven years, and overlooking that for the simple fact that he left when the next 1st-rounder had been traded is foolish, in my opinion. I did not have much difficulty replacing that owner, even though the team in question is not particularly good in upcoming seasons.
I think this situation would be worse if the guy just said, "I quit," and nothing else. However, I strongly feel that he should be believed, and given the benefit of the doubt. Five seasons is a pretty long time--that's what, a calendar year, more or less? Discounting that because he has traded a couple of picks is dumb, in my personal opinion. It's not like the team is an unusual position--it needs to be rebuilt. Rebuilding does take a while, but it's something every team must do.
Is it a great situation? No, obviously not. However, I don't think you should completely discount what he did do--manage a team well for like a year or so. Compare that to the plethora of idiotic owners one encounters in progressive leagues... there are much worse things an owner can do.