....anyway...

To an objective observer who has dug a little into the background...

It really could look as if Cliff has a long running petty vindictive grudge against the BBC...???
and is now acting like a spoiled diva with a massive sense of entitlement;
spitefully biting the hand that fed him,
that helped make him into a superstar...???

Reminiscent of a lengthy marriage which has turned sour and ended up in a bitter costly legal battle...
where neither partner comes out of it smelling of roses...

Yes, and to an impartial observer it could also look as if it is the BBC which is throwing the hissy fit.