I have to agree with Magic Banana, and I'm seeing a lot of unreasonable
paranoia here.
The "embrace and extend" or "EEE" strategy involves embracing a standard in a
proprietary program, and then adding proprietary extensions that competing
programs either can't implement or have a prohibitively difficult time
implementing. That's not what we're talking about. Microsoft isn't
"embracing" POSIX standards in Windows. What we're talking about is making
GNU/Linux programs run on Windows.
Take a moment to actually think about this. How, exactly, do you expect
Microsoft to use a system to run GNU/Linux programs for an "embrace and
extend" strategy? Yeah, sure, "embrace". But how exactly do you expect them
to "extend"? As Magic Banana already pointed out, most of these programs are
copylefted, so any changes to them has to be released under a libre license,
or not at all. In this case, there is no room for "embrace and extend".
On the other hand, I suppose it could be possible, but rather difficult, to
use the "embrace and extend" strategy with this plus proprietary versions of
permissively licensed programs. But Microsoft could do that so much easier
just by putting those programs directly into Windows.
These vague accusations being thrown out about "classic EEE" and pointing out
that Microsoft is evil? They're nothing more than conspiracy theories. Come
on, guys, I thought we were better than this. Of course Microsoft is evil.
All for-profit corporations are evil. That doesn't mean that everything
Microsoft does has some sort of secret agenda behind it.
So, why would Microsoft work with Canonical on this? Because it benefits
them, of course! It benefits both Microsoft and Canonical: Microsoft by
providing easy access to GNU tools (which they think of as "Linux" tools) and
some other programs, and Canonical by raising awareness of Ubuntu. There
might even be other benefits for either side that I missed. There's no need
for an evil corporate conspiracy to explain this.