Country is the 2nd most popular music format in American radio after Adult Contemporary, which is why after 25 years in radio, I do not listen to radio. News/talk is the most popular radio format, another reason I do not listen as I find it depressing that those people are not incarcerated somewhere and are free to roam the same country that I am.
For years, Country had a stigma attached to it of Bubba and Earline in the single wide comparing gaps in their teeth but it began to change in the 80's and really made a move in the 90's. This was in conjunction with the emergence of Grunge in Rock and the exodus of many listeners in search of something else. Some had already left with the breakup of the Beatles, the real "Day the Music Died" to a large segment of the audience. And Nashville took note and so did the label composers.
"Urban Cowboy" is given responsibility by a lot of consultants for the real take off and glamorizing Country and then there was the Elvis and Michael Jackson of Country, Garth and Country found a new audience and that image of the Grand Ole Opry was replaced by a huge arena act taking Country to where it had never been before.
So, unpopular really only applies to the Country haters, both groups. The ones that hate the twang and the ones that hate the Nashvilling of real Country.
I do not think most people look at it as a choice of Country or Rammstein, there is soooo much in between.