People who work in the Film Industry consider what they do to have a lot more permanence than the efforts of their TV buddies. For some time now, in America, it has been the law that ALL contributors of original material and effort be mentioned in the credits. The theory is that in years to come when everyone has forgotten who Robert DeNero was, the fact that Jarel Sprogg was the second Sagger Knitter's Window Dresser will be hot news.
The TV people in the UK generally just put up the main contributors, and not even a full cast list in a lot of cases. (In America they still have to show the whole caboodle, but then belt through it at a speed faster than which even the TV at 25 frames a second can cope. The TV people are very much aware of two money related factors. 1) their content and jobs are paid for by advertising (ok Beeb not so much, but they still want to keep you!) and when the programme content has finished anything that shortens advertising time diminishes revenue to the company. 2) They consider that a lot of people will reach for the channel change button or just stop concentrating once the credits start to roll and they will then miss those all important adverts. They try to keep you there by giving you the "Coming up next on this channel ... " voiceover and a split screen teaser in vision. It is all done to keep you on their channel, so you see their serving of adverts.