You shouldn't trust any platform vendor. If you're too small to get a contract stipulating that they can't pull the rug out from under you, you should start developing only after making a careful calculation of risk/reward.
For many many years ISVs made money in "the Microsoft ecosystem".
Yes, sometimes MS pulled the rug out from under them and/or directly competed with them with unfair advantage. But not really that often.
They certainly never "pulled your app from the store". I'm still having a hard time getting my head around that concept and why anyone would invest development resources into that kind of platform.
The questions is: "will I make money on this platform?"
The answer varies from project to project, platform to platform. But it has nothing to do with 'trust' in the platform vendor.
If your answer involves "I trust the platform vendor" you're not making a decision, you're gambling.
> "I'm still having a hard time getting my head around that concept and why anyone would invest development resources into that kind of platform."
It's a risk like any other. (Non-gambling) business-people accept risk when they think they can make enough money to offset it.
Oh, except for every time that someone made a large enough profit (wordperfect, visicalc, Corel Office, Peachtree or Quicken) or made a big enough splash (Netscape/Mozilla, google, more recently mint.com) in their ecosystem.
"pulled your app from the store"
But, they can if you sell on XBox Live Arcade, or Windows Phone Apps Marketplace (especially if you have an open source license for your app that MS doesn't like).
Right, we can list a dozen or two Windows products that were possibly competed with unfairly by MS. Over a period of 20 years.
The vast majority of MS Windows software products fail for reasons other than the platform vendor screwing them over intentionally. MS has known from the beginning that the success of Windows was primarily dependent on ISVs developing for it.
The XBox and MS Phone stuff seem like different things entirely. XBox is specifically not intended to be a general-purpose application platform. I can't imagine the MS Phone will ever require more than a free download SDK to develop for it, although this "marketplace" is likely to be a more reviewed ecosystem.
especially if you have an open source license for your app that MS doesn't like
It's not a question of MS not liking it. GPL, especially v3, is designed specifically to prevent binary-only app distribution which is the app store business model.
Trust works as in the real world: you choose to interact or start transactions with people that you trust. Contracts are indeed used for protection, but contracts also contain fine-prints not meant for mere mortals to read, that's why trust is still so important.
Also in the real world, people that often violate the trust of others are sooner or later marginalized, excluded from the social circles that supported them.
Risk/reward calculations sound nice, certainly within the skills of any MBA, but impossible to do in our industry and whenever I hear people talk about it sounds more to me like trying to rationalize a bad decision.
You shouldn't trust any platform vendor. If you're too small to get a contract stipulating that they can't pull the rug out from under you, you should start developing only after making a careful calculation of risk/reward.