This is exactly what we are talking about. We are looking at videos of some kind of end products (though this time they are only tech demos of Torque3d).
And sometimes we look at finished games (the gallery of Ogre, Torque and Unity3d or the new Instant action platform is full of them).

You are right, that workflow is not the only fact, especially not for professionals. You see this easily if you look at the raising amount of professional games made with Ogre3d. They even have to code their own editors. But they decided to use a flexible and powerful engine with full source code.

And I agree, you can make small Windows games with each of these engines. Some of them can even produce games for web browsers, iPhone, Wii or Mac.
The multi-platform availability can be important especially for small games and small indie developers. And having a good work-flow will help as well because we all have limited time.

And these are some of the reasons why a few developers are happy to see good tools, simple scripting, easy publishing to many platforms. It makes their lives easier, even if they develop very small home-brewed games.

Unity started to deliver all this and Garage-Games realized that they have to compete. And they do their best to deliver something similar. And as we can see they seem to reach this goal soon.