I also don't appreciate the jokeyness, I'm not a particularly good flyer (the result of watching too much air crash investigation) but I want professional/responsible staff who don't laugh on the tannoy, or amongst themselves.
I'm the complete opposite, which is why I rate Southwest so highly, their crews have a laugh while still delivering the required standards expected by passengers, I can't be doing with stuck up crew who don't look like they are enjoying themselves.
The best work places are those where staff are allowed a bit of freedom to express themselves and have fun, it would be a sad state of affairs if an airline frowned upon it's staff having a joke amongst themselves and the passengers.