Has nothing to do with it.

I've seen a lot of potential in Android, none which was utilized.
Such as the performance and intuitiveness of MIUI/Custom ROMs.
The features packed into it.
The thin, and high-end of certain devices.
And the design and feel of other devices.

Now here's the kicker.... there's no device that brings these together.
They all compromise, where a compromise is unnecessary.

Imagine if Nokia had decided to "go Android" ?
They could've built the first button-less device like the N9.
Bring forth the OtherHalf concept (not sure if this was an ex-nokia idea).
Nail the qwerty phones, and "weird phones" like the Kyocera Echo and NOTE series.
Then conquer the low-end/poor demographics.
Possibly built the Frontal Dual Loudspeaker concept before HTC One.
Made kickstands, useful ones.
Perhaps replaceable batteries on top of this too?

Anyways, the sky is the limit.
They had the resources and the ability to do so (if history's shown anything).

And doing so.... they could've turned around and still supported WP.
And at the end of the day... they PROBABLY wouldn't have lost as much value doing so.
In fact, they could've become a major contender as long as they maintained the mindshare of people.

Now what are they?
Not even a "third racer". After Samsung and Apple, people think about HTC, LG and maybe SONY. Motorola is also a contender.

So not only did Nokia shoot themselves in the foot... they decided to take a seat instead of limping while the zombies pursued them. I would've preferred Nokia get WP and become a successful third contender... but WP is so inferior to the other offerings in terms of customizability, features and support that its pretty funny.

Part of this is Nokia's fault. Part of this is MS's fault.
At the end, its the consumers who suffered.