I think it is more about getting too many cards within a time frame. I have excellent credit but did not start getting cards for bonuses till last fall...when the American Citi 75k offer came out. My husband and I both got the cards...then we got a couple of Chase cards, then an new Am Ex, then a new Capital One, then another Chase card..then I just applied for Alaska B of A and was approved...but then my US Airways card is pending review and I got turned down for the Chase Sapphire because I had already opened 4 new cards with them.
Guess I overdid it for awhile! As someone else said..time to sit in the penalty box and wait it out awhile before I get any new cards!!
I think the people on here with 20 cards took their time and spaced out their "churns". I went from having a couple cards with awesome credit...and then I opened tons of cards! My credit score is still very good, but it looks like lenders are backing off because they can see how much I am applying!