I always rate in comparison to expectations (i.e. an airport Holiday Inn that's clean and quiet with comfortable beds and working internet probably is going to get 4 or 5 stars, if I'm staying at an Intercontinental in a major city it'll take a bit more than that) but I agree a lot of people don't. I generally ignore any 1 or 5 star reviews from anyone who only has one or two total. I wish TA had an easy way to filter out reviews from anyone with less than ten.