It's funny you see it as lacking foresight, I see at as having incredible foresight to sign to a contract that guarantees the best of both worlds. 1. Ability to keep the player if he performs to your standards of the contract. 2. Ability to cut the player after 1 season for a large net cap savings while creating little to no dead cap hits for multiple years. 4 million in dead cap vs. 9.8 million in savings (or 12.5 million if post June 1st.)
Honestly, it was a master class in how to sign a premier free agent to a a deal that makes them happy while protecting your teams cap future. KVN was a good player and great leader. Flores and Co. just sent a message that the better player is going to play on this team, not the higher paid one. If you underperform they will make decisions that are in the best interest of the overall team.
You say that "he gave them exactly what he should have been expected of him" which is ridiculous too. Almost as ridiculous as the "pissing cap away amid a crucial rebuild" line. Once again, a maximum of 4 million for 1 single year, against 9.8 (or12.5) A minimum net gain of approx. 5 million in cap space for this year. Next year he is completely off the books when the cap should rise significantly. Also gives us more cap to potentially carry over a bit to next year if we choose.
Lastly, KVN was never going to be a backup here with that pay and that language providing an easy cheap out. If you read things like this you start to realize why they came to the decision to cut him.