That's a very good question.
I'm a new host and I have had three 5 star reviews so far.. I currently have a guest staying and I'm worried they are going to rate me down due to the fact they felt cold on day 1 even though the temperate is 22 degrees. They spent New year's eve out in the cold for several hours so came home feeling cold. Not my fault. Since then i have them extra blankets and a heater. I knocked and also gave them hot water bottles for bed time..when I opened the bedroom door it's like a sauna! Surely they can't expect it to be hot and toasty all day like that.
Technically I should give them a low rating as they are inconsiderate in the bathroom with splashes everywhere and unreasonable temperature demands all for £15 each per night.
A 4 star rating will be unfair.