I'm an older guy who has been enjoying this for a while. I like writing reviews and never try to extort a discount for writing them. If a provider says she does not want a review, I do not write one. I have not found it hard to write honest reviews that are not being cruel or insulting. It is not hard to find really cruel reviews.

Four kinds of clients seem to be behind most of the reviews that seem written to hurt providers that are honestly doing their jobs.

1. Clients who write as if their personal preferences are everyone's ideal. And that, if they don't do their research of the honest advertising that is out there and then have a session with someone who is, in their view, too old, short, heavy, small breasted etc, for them, then they trash a provider in a review.  
2. Misogynistic trolls
3. Clients who simply can't get it into their big heads that clients of sex workers and sex workers have similar worth as persons. The starting perspective is she's a slut and I'm a saint.
4. Clients who expose things about a session or location that endanger or embarrass a provider. This includes clients who review providers who don't want to be reviewed. Absent something off the wall, (e.g. a robbery), consent to be reviewed is separate from consent to what happens in a session.

Hobby nicely, YMMV.