The fact that the contract had built in "remedies" to avoid litigation should one party or the other fail to uphold their obligations as specified within it, such as the cluase that required the CVC to provide the Rams with a top tier stadium, doesn't excuse one party or the other from "choosing to decline" their obligation.
The CVC made the Rams a promise and within the contract itself said that if they failed to abide by the promise the Rams were free to relocate rather than sue. That promise is what got the team to St. Louis in the first place. The CVC broke their promise, the arbitrator agreed they broke their promise, thereby releasing the Rams from the contact as specified by the contract.
It is absolute spin to frame it as anything other than the CVC reneging on the promise they used to lure the Rams to St. Louis and suffering the predetermined consequences for doing so.