Presumably neither the BBC or the SFA decided to push this. The rules say:
”The Scottish FA, in accordance with the Articles of Association, may enter into contracts with commercial sponsors and broadcasters and grant certain rights as the Scottish FA may in its discretion determine (“Scottish FA’s Obligations”) to such parties in relation to the Cup and the Competition.
The Scottish FA will intimate in writing annually to all clubs eligible to compete in the Competition, the terms of the Scottish FA’s Obligations, which apply to such clubs (the “Statement”). The Statement will constitute a definitive description of the Scottish FA’s Obligations.
All clubs participating in the Competition undertake to provide any rights, facilities and other services as may be necessary for the Scottish FA to perform the Scottish FA’s Obligations.
Without prejudice to the terms of the Articles of Association, the Judicial Panel Protocol and the Rules and any other rule and regulation of the Scottish FA any failure and/or refusal by a club to comply with any of the terms of the Statement may result in the matter being referred to the Compliance Officer (as defined in the Judicial Panel Protocol) for investigation and possible sanction in accordance with the Judicial Panel Protocol.”
Reads to me that the BBC could have insisted.