I didn't intend to, though I can see how it came off that way. The point is that there is there is near zero certainty that Elop made the wrong decision.
The problem with that strategy is that they don't get MS's support payments, nor do they claim the #1 position for that OS. I highly doubt that the removal of Symbian from Nokia's high end devices hurt their sales much at all. Symbian's marketshare came overwhelmingly from lower end devices, and at the time apps didn't matter there.
In 2009, Apple had 99.4% of app sales, despite
Symbian having ~50% smartphone share. No devs cared for it, so the only people buying phones with Symbian were those that didn't care about apps, which was a declining demographic.
Look at the data:
Can you honestly say it looks like Elop accelerated Symbian's decline at all?
Widespread app development is a critical part to long term success. Apple had the first mover advantage (and for a long time it was gargantuan, given their relatively affluent user base), but wanted to remain a high end, high margin company. Google swooped in with a free product in a timely manner. These two could've been the only two significant players in the market, with nobody else offering any meaningful advantage and devs having no reason to care about other platforms.
The only reason MS had a chance to be a third player was their unified Win8 kernel/UI strategy. Devs have a solid incentive to make apps for all types of devices running Windows - laptops, tablets, and smartphones (and MS is throwing cash their way as well). BB and Symbian, MeeGo, Tizen, etc all had zero or nearly zero share of app sales in 2010 (hell, even Android was only at 10%, despite the OS marketshare being decent), and didn't have this trojan horse that MS does, so devs had little incentive to develop for them and that won't change in the future.
Android and WP were Nokia's only choices. Nokia wanted to take a gamble to stand out from the crowd, and MS paid them to do it. I can't say definitively that WP was the better choice over Android, as maybe Nokia could pull of a hardware or marketing miracle that LG/HTC/Sony/Motorola couldn't in their bid to unseat Samsung; however, I can say there is little to support the notion that Symbian/Meego had any chance in hell.