Since Apple runs the store, contacting the developer is an indirect way to get it looked at. The main thing as a user you can do is not look at reviews or sites you feel don't match your sensibilities.
Use the contact us link if you’ve purchased the app as there is no direct web link to report a violation of terms. Apple has a pretty strict version of what it allows in official metadata, but user posts need to have a little more lattitude IMO - just like we do here moderating.
Things you express your individuality in your profile or when you clearly state in an answer your opinion or experience is harder to "police" than the content of a question. The official app and the official post can be held to a higher standard of civility while balancing the need to tolerate different views and language expressions - what's normal, what's a valid criticism and what's a mean spirited dig or worse, trolling or inflammatory post just to provoke a reaction as opposed to convey how software is experienced.
If you are not a customer of Apple selling you that app, you would need to use the general feedback mechanism.
Unless the slander or offensive conduct is worth legal action, you probably won’t get a good response from Apple legal, but if there is a violation of law in your jurisdiction, then Apple legal has an email address for legal processes.
Once you’ve sent feedback including screen shots and a short summary of why you feel aggrieved by Apple hosting a review on their store front, maybe contact Apple Support to be sure a human knows you had this issue and confirm you reported it to the correct group / advocate.
https://support.apple.com/apps
