Because kids these days, they're not dumb? And they realized they can connect from other places than the computer in the home living room? From their personal cell phone, from a friend's place, from the school's computers and whatnot?
Actually, it's not like it's a particularly new idea, 3 decades ago, I knew how to watch certain movies in places lacking parental supervision.
Parents sure do have a role, but expecting them to be looking at their kids' actions 24/7, or even a portion of that, is unrealistic. Many of them would like to but have to work late, or simply lack the skills. Companies that make billions exploiting kids' data can help.