I love bluegrass (and can even get past its sometimes religious undertones if the banjo is good enough). I also enjoy lots of "old" country like Cash, Haggard, Cline, and even Dolly. But if some cruel wizard cast a spell so that ever other song I listened to was something from current popular country, I would choose to never listen to music again.
When it comes to country, here are some rules of thumb that predict it is terrible:
1. Are there any patriotic symbols anywhere?
2. Do they write any songs praising America or the military?
3. Are there more than 5 people on stage (especially if there are "backup" guitarists who get no real credit)
4. Do they sell out massive stadiums? (exceptions are some old-school acts that now sell out stadiums to decades worth of fans)
5. Do they have any songs about the wonders of faith or how much they love their kids?
6. Are they male but the majority of their audience female? (not relevant when the musicians are female too)
7. Do they bear any resemblance in any way to Brooks and Dunn?