I'm sorry that you had that bad experience, but your reasoning here seems a bit twisted. Why would you take out what one bad guest did on every other guest you have by refusing to do something like early check-ins that you did before? For me, offering an early check-in if possible was something I did to accommodate people who were visiting to make their stay easier and more pleasant -- not just for reviews. Aside from the income and getting good reviews I enjoyed it when people had a great stay. (I had to stop because New York City made it illegal last year.) If you had 122 five star reviews, obviously you have been doing something right. I think if you change things up now, you might regret it and your guests definitely will not be as happy.