You're right, so the informed customer is likely to avoid both Google (and other large companies where the product/service isn't the core business) as well as startups.

It's unfortunate for startups, but also a reality. For large businesses, they can mitigate this effect over time by sticking by anything that they launch and seeing it through. Microsoft did that to an extent beyond what anyone expected when it came to Zune, for example. Google has developed a reputation for doing exactly the opposite. In fact, with Google Wallet they're shutting down pretty much the most compelling payments service for digital goods that the web has seen. Why? They never promoted it properly, and as a result web developers generally don't even know it exists.