Because sometimes free food is not worth the calories it takes to chew it. Included:
-doughnuts at work
-melamine supermarket chocolate
-dopey free "yeast rolls" at feed trough places like Ryan's and Golden Corral
-that orange soupy stuff that they say is "nacho cheese" and it comes in one of those woven wooden bowls at the gringo "fast casual" restaurant before your sucky gringo chalupafajitaplaaaatter or whatever bunk thing you ordered because there was nothing on the menu that was NOT bunk. Don't eat that glue, damn.
-all stuff like the above
See the thing about all this stuff is, it is designed to be not all that great but nevertheless make you ravenous so you eat more food that costs money. It is like if you go to the gentleman's club, what they do on the stage in order that you should order a lap dance and then have your Lancelot urge kick in and get into a bad marriage and end up driving around in a sad kind of "married people" type car. That's what those chips and orange "cheese" really represent. Stay away.