It's all about the 'chemistry'.
BTW, the definition of 'chemistry' for TV execs is -
attractive woman / ugly grumpy man interface exposed as ludicrously unreal by forced proximity and gentle innuendo intersperesed with meaningful glances created for the folllowing reasons -
MAN - I have never been this close to an attractive woman without helping the police with their enquries afterwards. I would jump your bones in the time it takes to blink, and I spend my nights crying myself to sleep because it's never going to happen, and seeing that reality every time you look at me almost makes my eight-figure contract not worth the pain.
WOMAN - being connected with you is the only way i am going to get a high-profile TV gig, and i have to pretend that there is an unspoken attraction between us. In reality - somewhere I live, and you don't - I wouldn't touch you with a laser map pointer, and I shiver every time you press your sweaty thigh against me and look at me like a poodle hoping for a buscuit. I can't wait to get away to my footballer boyfriend who is everything you are not - talented, handsome, virile, uncreepy etc. I just pray my agent can get me a solo show as soon as possible - pretending to sile and laugh is causing havoc with my jaw muscles every day. Oh, and stop ringing me at 3:00 a.m. and haning up, I know it's you!!!!
So, as you can see, it's really never going to work is it? the pity is, these execs are paid seven-figure salaries to come up with this nonsense!