I have a theory about these people -- they are the ones who never realized that you could search Maps for place names.

If you search for street addresses, both Maps implementations perform OK. But the strength of Google's database is that you can type almost anything within reason into the Maps search box and get where you want to go. For my first few weeks of iPhone usage, whenever I wanted to find a nearby "Starbucks" or "Barnes and Noble" or $name_of_local_restaurant, I'd do the search in Safari, pick a likely result, and then click on the page's address link, assuming there was one, in order to open it in Maps. Eventually I realized that I could type the search string directly into Maps, and that made life a lot easier. If that stopped working or became less effective on the iPhone that I use for navigation in the car, I would scream bloody murder.

So my guess is that the people who aren't complaining about Apple's maps application are either living in metro areas that were carefully vetted by the data provider, searching for street addresses directly, or both.