Why everyone picking Kansas City like they are the big favorite, and surprise by Oakland play?

Yes, Kansas City 5-2 they improve this year, just like Oaklland. But people are talking like Kansas City been a power for years. they been in last place for last three years worst record than the Raiders. 2007 4-12, 2008 2-14, 2009 4-12. Have not been to Super Bowl since the early 70's.