Perhaps the stumbling block here is that Reader is such a bad example, since it is mostly for consuming content non-interactively, and applications that use the Reader infrastructure won't have a difficult time replacing it. However, that neglects the importance of network effects for Google, developers and users.

Maybe you recall a chapter in Cannery Row where a gopher sets up in a perfect vacant lot full of everything it needs and without predators. (Or not, and I suppose the value of allusions rest on the network effects of a common canon) The gopher flourishes, but ultimately gives up because no female gophers ever appear, and it returns to a garden with gopher traps set out. The allegory is an accessible way to explain network effects, something that is often lost in the entrepreneurial rhetoric, where companies succeed or not regardless of the market environment or context of the community they foster or don't.

When choosing a large development platform, anyone reasonable doesn't only look at the tools and languages, but also considers the community and the market. Take for example Blackberry or the Windows Phone. I don't think developers believe that anyone owes them certain tools, or even a guarantee of a certain number of sales. However, these platforms will only get good talent if there is a credible marketability of anything they develop.

Hypothetically, lets assume that Visual Studio works really well for developing on Windows Phone and is better than any other set of tools for mobile development. Then let's assume that in 2015, Microsoft stops creating phone operating systems because the phones remain unpopular. A lot of developers have spent a couple years learning skills, much of which they can use elsewhere. If they'd been developing for Android or iOS, they would have even more skills that would be useful elsewhere. Now, someone shouts at you, "So you're saying that Microsoft shouldn't have released such a good set of tools?!" The question itself is silly.

The problem is not reducible to a set of tools, or evangelizing to developers, or confidence in the platform, or advertising to consumers. Assumptions about all of these together go into developers' decision making today, and it isn't even that deterministic, since there's an error component to how these perceptions that aren't based on accurate future-prediction, that will itself decide the future success of the platform.

The original Economist post didn't so much talk about Google owing anyone anything, but addressed the confidence problem. If people believe that a product won't be around very long, it won't get talented developers which won't attract users, which will lead to the product being canceled, or vice versa.

Let's say you want to put a small module on your webpage, and you are considering Google Gadgets. It might be more difficult to replicate the same functionality using HTML5. Are you worse off, because Google Gadgets is available? Google doesn't owe you any guarantee about the longevity of the system, but it would be more valuable right now if you could believe that Google Gadgets will still be around in a couple years, and your payoff matrix says that you would be worse off if you choose Google Gadgets over something else and it is later canceled.