No it's not strange to see the same teams in the playoffs. It's always cyclical when they're in dominance. Look at all the periods for the NFl and you'll usually see the same team in the playoffs for several years on a row until the key players retire or are traded and the rebuilding process begins again.
And NASCAR? *shudder* I'd rather watch paint dry.
“That's it. You people have stood in my way long enough. I'm going to clown college!”