I've worked at companies of all sizes, and at every one of those jobs, I've had some form of MSDN access.

I've never ran into the issues you're referring to. Microsoft makes it both easy and cheap to obtain development licenses for their software.

And making it free, at least initially, for businesses removes the requirement of having to have a conversation about it or get permission. It's the same way Dropbox gained so much traction (arguably, the first to execute this model).

You let all of the employees use something for free, come to rely on it, and then all of a sudden it's become entrenched in the workflow/culture/whatever. At that point, it's easier to just pay for the service than to switch.

See Slack.