You know why you don't ever hear that piece of common sense?  Because it's not a sexy slogan.  It's also not very marketable.  Companies can't make money off of it like they can when they offer group meetings, a "low carb lifestyle," or some other diet or program.

We need to accept responsibility for our actions and stop trying to find a boogieman for why we shouldn't try to lose weight and why we fail when we do.  I had to stop blaming McDonald's for "forcing" me to eat there four times a week.  I was obese because of my lack of moderation over 20 years.
 McDonald's itself didn't and doesn't cause me to gain weight, but my choice to go there and consume excess calories on a regular basis does.

Does McDonald's have food that some consider less than nutritious?  Absolutely.  Is the majority of the food they offer high in calories?  No doubt, so don't eat there often or at all, that's your personal choice.  When you do, limit yourself.  If you don't limit yourself, then burn extra calories that day or be diligent for the next couple of days afterward.

I'm not saying that there aren't things in this world that have a greater influence on our waistlines because that's obviously not the truth.