I hate this sort of comment, are you comparing the time and knowledge needed to teach a subject to your children such as chemistry to something very basic such as a simple command? If it's so essential as OP says then surely the majority of adults know how to do it?
@Unithorn
That's a massive set of potentially misplaced assumptions there. It's like assuming every home has a selection of books or access to books (Kindle, etc) and speak standard English, and wondering why twelve year olds are struggling with reading.
You're starting by assuming parents have been to school or have grown up in a developed country.
Then you're assuming they have a job/hobby/lifestyle where keyboarding or word processing skills are used.
Then you're assuming they have a laptop or PC at home.
Keyboarding is absolutely essential in many industries and will only increase its relevance as time goes on, and the majority of adults are not capable of doing teaching current or relevant skills to their children in a way that is thorough or systematic.
For those who don't and who struggle with the very basics they'd be supported in IT/Computing at school, but there's no value in using that time to teach everyone stuff the majority know, could Google and find out, and of which recent Office versions actually prompt when you complete the action with mouse.
There is a huge value in having a specific keyboarding course that all students must pass, taught by a qualified teacher, with a proper assessment rubric for skills.
The material covered can be kept up to date for workplace requirements, and it can be general enough to cover many industries.
Again, the assumption that the majority of students or their parents would know how to generate and manipulate a spreadsheet, create a power point, create and manage databases, create and use graphics, or know how to use applications used in marketing or management, or basic business concepts is completely misplaced. My DCs' coursework in high school covered all of that and more, and their skills were assessed by means of several complex projects assigned during the school year.
As my DCs have progressed through university and into careers, they have built on the foundations laid in school, and they have embraced all the requirements of their jobs with confidence.