If Journey recorded a song that sounded like One Direction and released it under a fake name, with no pictures in their press release, it'd be all over radio.
If Journey recorded a song that sounded like Journey under a fake name and a press release that said they were all 21... it would still tank.
The only reason the Donny Osmond hit did so well under a disguised name, was because it was completely different musically.
Same thing has been done by Cliff Richards and The Alarm over here.
But it's because they are releasing something that's totally different from what they are known for and that's why they release it under an assumed name to get it a chance.
You could release anything off of the new Pride Of Lions or Lionville or AOR or FM, etc under a fake name and say they are all young guys in their 20s making great music in the press release... people will still not like it because it doesn't sound like current music.
Dare, FM, Thunder and The (very well connected in the music world) Answer have all had radio play on mainstream British radio, and Thunder even charted, but it never lead to huge success or the re-birth of melodic rock. Journey is played almost daily on mainstream British radio with Don't Stop Believing. How well did anything off of Eclipse do as a result of that?
So no, more radio play won't make a bit of difference.
And in answer to the question in the title of the thread, Why isn't it popular in America? Why would it be, it's not popular anywhere else either... :-)
It's a niche market, and that's why we have this site and little festivals like Firefest and HRH AOR. That's more than alot of other genre's can hope for, and laughably small to others. It is what it is.
Niv