That's bs. You obviously have no idea what's going on k-12 math classes. (that covers a *lot* of territory)
Okay, go on then, enlighten me, what are students expected to learn in K-12 mathematics classes?
Given that programming was dumped on little kids in the 80's and early 90's and didn't yield useful results, I think it's ignorant to think it would a second time around. Programming classes make sense for high school electives, but anything more is just a waste of time. That's why elementary and middle schools don't really bother with it anymore.
Back then, computer use was not as pervasive a part of our culture as it is today, computer skills were vaguely understood to be important, but the reasons why were poorly understood.
Nowadays, computing is everywhere, many more people interact with computers on a daily basis, and there's a stronger understanding that programming skills are useful in a wide range of jobs.
To summarise; whilst before there were good intentions without much insight on how best to capitalise on these intentions, nowadays we have good intentions plus a drive to improve computer literacy beyond the state it's at today. That's why it's more likely to work this time.