Do you have kids? Giving a rear facing toddler legos, puzzles, anything that fits in the mouth in a car is not responsible parenting. It's not like I could just reach back there and grab something if it became a problem. An electronic device in a case designed for kids, that allows her to learn colors, letters, etc. is much safer than letting her choke on a lego.
Legos also won't cut it for some kids when you have two nurses and a pediatric neurologist trying to pin your child down to start IV's and do medical tests on a regular basis. Don't be so quick to judge that every parent who hands their kid an iPhone, etc. are irresponsible people robbing their kids of developmental hands on play.