I know people who spend hours dragging the map around in Google Earth. And while I'm sure that a lot of people are going to the terrain maps via a search, there's most certainly another large chunk of people on there just dragging the maps around (I do it myself in a number of mashups/web apps that I visit regularly).
Given the post's examples, I think the critique is more than warranted, and I also think you're underestimating the benefit of prioritizing the labels.
Consider this: if paper maps disappear (along with the newspapers), shouldn't there be something marking the seas, mountains, and deserts?
Replace "Terrain" with anything else and that's pretty much the subject of all of this blog's entries. I don't know why the naming on the terrain maps would be any better than the labeling on any of the other map modes.
Incidentally, I think Google Maps is one of the coolest things ever... I used to love to look at USGS quad maps as a kid, and now I get something that is 80% as good for pretty much the entire world. How cool is that...
To me, "terrain map" means "physical map". If the "terrain" maps are intended for hikers, Google should instead label them as "hiking" maps. But I doubt that they are intended purely as "hiking" maps... none of the trails near my house are on them.
They're compiled, I think, from whatever they can get their hands on. It's interesting to see borders, for instance, where there is clearly a difference in the data available. Switzerland, for instance, seems to have really good data:
http://maps.google.com/maps?f=q&source=s_q&hl=en&...
Austria... not quite to the same level of detail.
