I can't authoritatively explain exactly WHY, but country radio fans - even our 55+ audience - loves today's country as much or more than they like 'yesterday's favorites.'
This is a wonderful thing. The same songs and artists which attract our growing 20-something converts today also, if chosen selectively, can hold onto 45+ and 55+ at the very same time. If you've done country for very long, you may be taking this attribute for granted, but please don't. (and, don't assume that it will always be this way!)
Imagine how it feels to a once-successful PD or personality looking in the mirror and realizing that what you have done for a living for decades is now only available to a niche audience on the internet?
A major group's VP/Rock Formats once asked me to "explain why country radio fans seem to be the only adults who seem to like new music."
Of course, I tried to do so (I do have my theories), but FIRST just smiled broadly and answered: "Thank goodness, that's a fact."