It wasn't always that way. Problem is, when cheap shitty fast food cranked out by McDonald's is what gets bought, cheap healthy food you have to take the time to cook for yourself becomes less and less profitable.
It's not necessarily laziness, often people just feel they don't have the time to make food when they've got a million other pressing concerns like long shifts, juggling who's picking up the kids from school, etc. Picking up some burgers at the drive-thru or throwing some pizza snacks in the microwave suddenly becomes a lot more attractive.
But yes, LOL @ this thread turning into Caffiene Addicts Anonymous debate: Sugar v. Splenda.