I dont think they do it because it "looks" cool. It is like a driving a car and making a sharp turn at high speed and feeling the g-force. It is that feeling of all your body weight is pushed to one side but you are moving in the other direction. next time you drive try to make 90 degree turn at 40-50mph and see if you like that feeling. If you do, you will prob like to do these.
EC is fun, but unless you are blessed with steeps, or good fast conditions (good as in fast, not slow, hero snow on a fairly flat pitch is slow)... you bleed off way too much speed.
EC is also dependent upon conditions. chopped up pow is easy. You can literally "snorkel" in fresh pow with a solid base underneath. If you don't extend all the way you can lay it down on slightly bumpy ice, but your ass will tend to be slightly up in the air...
Respect for these guys riding but it's not my thing. Well, actually it's not that it's not my thing, I want to do everything in snowboarding and focusing on one thing to that degree would limit my time to spend on other aspects. Deep, laid out carves on groomers are fun, though, so I can see how it could appeal to the point of specializing in it.