I agree with the OP. This is an issue which has personally affected my enjoyment of this game. The biggest reason I play Bethesda games is that the worlds they make are amazing, and Fallout 3 was no exception. It was filled to the brim with locations, even if many were small, and you were never walking around for a long time without being able to see in the distance a new location to explore. In New Vegas, on the other hand, I've found myself walking for minutes without finding anything new aside from a few enemies to fight. There are many, many parts of the Mojave Wasteland that are disgustingly empty, with only hordes of enemies placed there to give the player something to do. Perhaps the most noticeable place, aside from the huge, relatively empty area north of New Vegas, is the Colorado River. When I reached the south portion of the river, I decided it would be interesting to swim up it to the Hoover Dam. Now, I know for sure that if Bethesda made this game, there would be tons of locations along the banks of the river. Abandoned shacks, caves, maybe even a small settlement. Nothing major, but still something. Obsidian elected to add absolutely nothing there other than a few crates of explosives and dozens and dozens of enemies. It was so boring. I've explored about 70% of the map by now, but swimming the Colorado River is really what proved to me how much Obsidian pales in comparison to Bethesda in this regard. Obsidian improved almost everything in Fallout 3. The quests are longer and more complex, there are more towns and cities, more factions, more interesting factions, a better story... but they just didn't get the actual world they gave us to explore right.
I'm just quoting this to back-up my original point.
I'm not saying that the Mojave Wasteland lacks in content or depth, but I can literally walk for 15 minutes and not come across anything interesting (which is strange, because by using console commands to look at all the map markers, they all seem packed together). Perhaps it's Obsidian's placement of locations/enemies that bugs me. A good portion of the map is inaccessible/completely empty (see for yourself, tmm 1 in the console, look at the far North, East and West), and what few enemies I do come across are easy and usually by them self (Radscorpians mostly).
...or perhaps my game's bugged and some new locations aren't registering. xD
Oh, and the bold bit of the quote is something I definitely agree with.
EDIT:Read a few posts about how deserts are generally empty. Just to clarify, I'm aware of that. xD