It's not entirely devoid of value, but that doesn't make it a good idea. Junk food contains healthy ingredients, too.
It's a missed opportunity.
40 years ago my parents had a close friend with a young and irresponsible wife who raised their child in front of a TV. At 4 years old the child could barely speak. My parents began babysitting and helping socialize her. Now she's a successful businessperson herself and is doing quite well in life.
Studies on the impact of media on children are informative but don't lose sight of the fact that kids are adaptable and will overcome most kinds of sub-optimal upbringing.