Re: a large install base is their number-one criterion when picking a platform to write for
While your logic should stand on it's own, unfortunately in the laws of mobile, the adoption rate (aka the user-base) also indicates the prowess and willingness of the consumer to go out and reach out, find, download and use the 'app'.
In fact, I can tell you for a fact: having seen a person follow your adage with WinPho7. It's quite the opposite of the outcome you predict.
A small platform is just that. A dead 'ecosystem' where even those who are in it are trying to claw their way out and minimize their losses by not sinking any more investments into it.
Would be cool if it wasn't the truth. I'd be laughing all the way to the bank in November followed by February with respective WinMoPhoRTDesk8 and BB10 releases.