So one should never be able to leave the employ of the Astros? Seriously...what's wrong with "JD's outstanding skill at his job earned him a promotion"? Why does it have to be that the Astros somehow fucked up?
Deshaies was under contract until February, and thus the Cubs had to ask the Astros for permission to interview him. It is certainly conceivable, is it not, that if his contract ran through February 2017, they wouldn't have bothered?
I think the basic viewpoint being expressed by some here (myself included) which you seem to so vehemently disagree with, is this: the Astros should be bending over backwards to retain the fans that they have right now. The fans clearly love JD and clearly did not want to see him leave. Therefore, they should have gone all-out to attempt to keep him, either by signing him to a long-term contract earlier (as Footer notes, their practice of giving out 1-year contracts is risky), or by making an overwhelming counter-offer to what the Cubs offered him.
Would that have guaranteed JD accepted it? No, of course not. It is certainly plausible that they could have offered twice the salary the Cubs did, and he still would have gone to the Cubs. The point is that, from EVERY report out there, they made a "fair" counter-offer. Not an "extremely generous" counter-offer, which, to me, is what they owed the fans, and what would have been smart from a business standpoint.