Maybe, though I still have my doubts if it's the only reason.
If you want to standardise your user base, you don't force push the upgrade, you offer it.
I do not claim i know there is another motive behind it, but for me when a business offers me something for free i ask "what's the catch?"
I have been taught there is nothing truly free in life, everything comes with a price, some have a monetary price, others are more hidden.
For example, while linux is gaining in popularity in some places, Linux is still not standing up to Windows in gaming, though it is striding in the right direction.
the price you pay when using the free linux distros is that you don't have the windows compatibility for gaming and such. it's a price that is not monetary, but it does take away something from you.
For me personally if i can't see the price i have to pay for it, I suspect it until time proves otherwise.
Might be just me, but until today this instinct served me well.
-- 10 Dec 2015 23:53 --
Also, this guide was written for those who don't wish to upgrade or shouldn't upgrade because they need programs which are yet to have support on windows 10.