The amount of times I hear people say similar things but when they've been out of work they flat out refuse to do a job "below" what they did previously.
Most people who say this type of thing are full of it.
If you would personally work at McD's when out of work - fair play - but most people just use it as another reason to talk down to others.
I guess it depends if you need money or not - personally if I lost my job, I would work anywhere practically to make sure I had money coming in whilst looking for other work - it might also cure some of the boredom people in this thread mention!