Fake reviews on the Google Play store

I found lots of reviews where the reviewer gave 5 stars and wrote "I can not recommend this app" or "complete disappointment" and then mentions the name of a shady competitor website. Such reviews are found on multiple apps of the same category. One of the reviews has been online for 3 months now and has received 21 "likes" causing it show up near the top of the reviews list. This is a reviews for an app that has 500 Million downloads. Google is not moderating reviews properly even on popular apps and allowing abusers to plug in the names of their shady sites.