@Jing17 I agree with others that you shouldn’t shame them in your review, just mark them down for cleanliness. I would feel disrespected if it had happened in my house but I would leave emotion out of it. I’m a professional cleaner with impeccably high standards and one thing I’ve learned over the years is that everyone’s standards of cleanliness are different (people think it’s acceptable to leave their dried up poo round the toilet bowl for me to clean up -something I wouldn’t do if I had a cleaner).
Referring to another thread that I read yesterday, there seems to be a feeling that. the mentality of guests is changing, with people expecting hotel standards in shared homes. It could be that these guests thought of it very much like a hotel, which are discreet (probably because they don’t have a guest review system in place), so you could maybe say in your review that they’d be more suited to a hotel rather than a shared home.