Catman,
As far as I know there is no ban on bringing in outside food or drink (except alcohol) aboard a flight on most airlines. Considering that most flights in coach get a "bag nasty", if anything at all, it's not surprising.
BTW, if you haven't already heard, you can get Krispy Kreme donuts in Las Vegas! (Can't find 'em in south Texas, though

)
And yes... it
is a mortal sin not to share donuts with the overworked FAs!
AlphaSigOU