Why would a host turn away 20%+ of guests?

If you ask me to make an exception to my Maximum Number of guests just for you, I'm going to turn you down. But... But... we'll bring sleeping bags and air mattresses. One of us can sleep on the couch! Uhhhh.... No! My maximum occupancy in a One Bedroom, One Bath apartment is Two!

If you tell me about a Family Reunion, and ask how big the dining table is, I'm going to say No.

If you tell me about a wedding... and ask if friends can drop by while you're in town, I'm going to say No.

If you tell me that I'm more than twice the price of the Motel Six on the other side of the river, and ask me for a discount, I'm going to say No. And I'll suggest that you check the rates of the Bed and Breakfast next door... which is twice my rate... but half the rate of the Bed and Breakfast two blocks down the street.

If you've stayed with me before, and I didn't leave you a review, I'm going to say No. Because... if I didn't leave you a review, it is because I'm from that group of people who believe that "if you can't say anything nice in a review, don't say anything at all."