What can forum masters do against posts which lower the sales rates?

Only give negative feedback? Is this the explanation of negative feedbacks in the EEVBLOG? https://www.eevblog.com/forum/testgear/how-to-solve-the-ti-ads1299-eeg-demo-kit-is-not-save-for-humans-problem/ And negative feedbacks in the www.opeenBCI.com forum about OpenBCI modules from Aliexpress and WIFI shields? https://openbci.com/forum/index.php?p=/discussion/3815/aliexpress-cyton-knockoff-for-sale-200-obo#latest