I can understand not wanting to post a negative review based on nothing but a lack of being impressed. I tell you I don't like lemon pie, you think I'm crazy. You tell me you don't like cherry pie, I think you are a freak of nature.
Everyone's experience is subjective to a point, so bad reviews should be about services not your impressions or interest. If she's not your type, that's your problem, not hers. She can't control chemistry.
Really "bad" services, like not giving you the time you paid for, pulling a bait and switch, not providing what was offered to get you in the door, etc., is reason enough to review.
When I started all this, I knew the key to building a good website was the combo of ad pages and review board.
Reviewing the advertisers here, keeps out any bad providers (no provider in her right mind would pay me for an ad with a lot of bad reviews) and it gives potential clients confidence in the advertisers who are here. It's a self sustaining quality control. I have no idea who I am advertising until I read a review.
I was asked why I allow bad reviews by an advertiser once, and I told her "If I censor out bad reviews, everyone will just leave the board, lose trust in who is advertised here and the site will just die off like many others".
I've seen good providers get bad reviews here and most of the time, they get MORE business because the review is questionable. Curiosity tends to turn a profit.
Bad reviews of non advertisers is good for this site as well. If she wants to dispute the bad review, she has to get an ad.
Bad reviews also provide more information to visitors and the more useful this site can be, the more it will be used, the more clients the advertisers get, the more advertisers I get. Everyone benefits.
If a provider gets a really (well deserved) bad review and it costs her an income, then she needs to get another job. This isn't charity, it's a mutually beneficial business and all businesses should be held accountable. Especially one that involves a substantial amount of money.