Majority of the video posters go for the crazyness of it all, just to put it on video and display the amount of power their system has. Like Access said above, it all depends on what the user wants. Brushless systems will give you far more adjustability than nitro powered engines. They are two different worlds anyway.
Then you have the people who want power AND control at the same time
http://www.youtube.com/watch?v=3I9kzZjPxdI
It's no different than getting a nitro-powered touring class model and putting a very powerful engine in it.
You can have a T-Maxx with an after-market super powerful engine that will do what you see people do in the videos with their brushless systems.
It doesn't matter what the source of your drive is, it matters on how you want to use it.