These are among what developers would leave behind if they choose to abandon Apple for uncharted and unproven platforms of other vendors. Users do not follow esoteric open/closed platform politics, they vote with their money for convenience, reliability and value.
In order to become a better garden for developers, it’s not enough for other vendors to offer something that iPhone or iPad doesn’t. They have to match and better Apple’s current iPhone OS driven devices across all fronts. webOS had multitasking but no content. Nokia has market share but no direction or excitement. RIM caters to enterprise but not much else. Motorola still thinks it’s enough to manufacture handsets and leave everything else to ‘partners’ that turn around and stab you in the back. Android may be open but is currently a geek ghetto with nothing to match iTunes store. And, let’s not kid ourselves, Google is there not to ‘help’ but to commoditize hardware manufacturers by funneling them to compete against each other on Google’s platform largely on price.