ADC doesn't prohibit you from selling apps submitted to the contest (though you need to have a free trial for judges). Granted, there is less of a market for Android apps at the moment, but you are also less likely to have your app lost in a sea of lighter and fart sound apps.
It's not about being "lost" it's about total revenue generated. I haven't heard any revenue success stories from the android land (which is probably why they feel compelled to jump-start the app development process by awarding those prizes).
Perhaps its because the iphone app store has gotten about a 1.5yr jump on the android market. Give it time; with it supposed to be on 18 phones by years end, their will be users! - just give it time.
The above might be the wishful thinking that open source will win out (however debatable the openness of android may be, its the closest we got right now)
"The ADC 2 contest is open only to applications that have not been published -- whether through Android market, a public web site, or any other means."
I wonder whether apps ported from another platform are eligible.