I don't think it is as unintuitive as they describe. Frankly, it works very similar to the way it works at maps.google.com. There isn't a button at the top right near the other map types for Street View since the application (both website and iPhone app) doesn't know which street on the map you want the Street View for.

I think the issue is that they were trying to find Street View out of context of real world use. If I wanted to see street view, I'd want to see it of a particular location. Search for a POI or a street address and the pin will appear with the street view button. Granted, the button itself isn't terribly obvious in function-- I'll give them that. But their main contention, "Street View only becomes an option when a pin is showing on the map" seems like the right approach to me. Without a pin as a result of a search for a POI or address the likelihood that the app would pick the location and direction you want a view for seems slim.