Except that kids will need access to VS2013 or 2015, which, unless they have a parent who works on the MS stack.
That said, I do agree this is really a neat thing from MS.
Although it is not necessarily cheap, Youth Digital's Mod course[0] is really quite good. You get an instance of Eclipse ready for Minecraft mod development. While it covers some basic programming skills, it really about simply learning how to manipulate the code in order to do neat things in the game. My older boy loves it, and enjoys "exploring" by modifying parameters.
I can see how you may have missed Visual Studio Community Edition[0] in the recent flood of awesome MS announcements but it's been around for a while. Comments on the extension page suggest it works for this.
I can see how people missed the Community Edition, I cannot see how people don't know that the Express Edition has been free since literally 2005[0]. The only real difference between the free express editions and the community edition is the ability to install Visual Studio extensions, but broadly speaking it isn't that big of a change from Express 2013 for Windows Desktop.
If people don't know that Visual Studio has had a free version for 10 years(!) then they have their head in the sand. But it seems a lot of these people are common, often making bad jokes about IE "sucking" (hint: it doesn't, even pre-Edge), Windows being insecure (hint: it isn't post-XP), and Microsoft being a monopoly (Microsoft's market influence is nothing like what it was in the 1990s, between OS X, iOS, and Android it has a lot of legitimate competition).
That said, I do agree this is really a neat thing from MS.
Although it is not necessarily cheap, Youth Digital's Mod course[0] is really quite good. You get an instance of Eclipse ready for Minecraft mod development. While it covers some basic programming skills, it really about simply learning how to manipulate the code in order to do neat things in the game. My older boy loves it, and enjoys "exploring" by modifying parameters.
[0] http://www.youthdigital.com/minecraft-mod-design.html