"I'm afraid we'll have to leave it there..."

Why does every TV news interview finish like that?  
How about, “Thank you very much for your time”.  Or just, “Thank you <Name>”? 

Every single television interview I see always ends in that messy way.   

For 1, it’s a bit rude.It’s a bit like a shopkeeper, once someone has handed over their money, saying, “I’m sorry, you’ll now have to leave my shop.”  
 
For 2, if it’s the end of the interview – it’s THE END.By saying, “we’ll have to leave it there” suggests there’s more – but they’re not going to ask.If there’s more, ask it, and let the producer (who probably only allocated 17.83 seconds for the interview in the first place) deal with the consequences.  
 
There’s more, for 3, in TV time is precious - so why waste it with a long sentence?Just say “Thank you”, if they need to pad for time, they can ask another question – and finish the interview.  Maybe? 
 
And then, they [the presenter/newscaster/“journalist”] go on to introduce the next reporter as a double barrelled person.“There live for us is Ian Ramsdale - Ian…”  
 
When I was at school if you said some people’s names once they said “that’s my name don’t ware it out.”

But why is there a reason for saying it twice anyway…?! 

Don’t even get me started on the start on that one…

Rammo

Monday @5

Tuesday @7