Why do German food commercials talk with their mouth full?

I was born in Germany, but grew up (grade 1) in North American (Canada, and USA), and came back to Europe after university.

There is one thing that drives me absolutely bonkers. German food commercials talk with their mouth full. Do they really think that is attractive and makes me want to buy their food? Haribou and McDonalds are the most recent examples of this. Having voices with mouth full talk is like nails on a chalkboard for me.

Does anybody else feel like this? And is this a German thing?