Not in my experience. Yes, if you want to get a software development
career then HR departments usually 'insist' on a degree. But there's no way in heck that a degree is a requirement to learn programming. Far better to have the time to roll up your sleeves and get stuck in.
Powershell's got it's place, but why the heck would you narrow yourself down to something that - since we're speaking in unsupported generalisations like your '80%' figure - pretty much gets outsourced to India etc? I'd also be VERY wary of trying to learn programming with it - anymore than I'd recommend learning oil painting with a hammer. If the OP wants to stay in the Windows area then I'll say that C# would be a far better choice than Powershell - not only is it a 'proper' programming language, (rather than a scripting one), but as such there's a whole wide vista of 'real' jobs you can do with it, (at least once you add in all the .NET stuff). Heck, might even be able to persuade him to port his C# masterpieces to Mono and get some cross-platform availability.
By the way, I just came from a very large 'shop', specifically HP Enterprise Services (those fellas with the green rectangle as a logo) and their key in-house Windows admin tool is overwhelmingly written in Python. Mainly because, according to the developers, since Python runs relatively quickly and is cross-platform. I've also heard that IBM Global Services also use a lot of Python, along with substantial amounts of Perl code.
Actually 'markg1981', I'd have a look at
Comparison of programming languages as this gives a pretty decent overview of what's "out there". Good thing is that a lot of the current ones are available as either open source implementations or 'free', so if you've got something that'll run x86 code then you're good to go. Of course, the ole 'Pi also seems to have a goodly selection of the 'current' languages. And it's not as if a gaming PC style 'monster' is needed to host a decent dev environment (I did a good deal of dev work on an eBay'd Core2Duo laptop, which was more than capable of running a host OS and a couple of Windows/Linux/Solaris/etc VMs).