Corporations being "fictive person" (whatever that means) isn't a relevant factor. What does matter is that they are legal persons[1], and therefore can sue people under tort law. It's not hard to find defamation cases where corporations are the plaintiffs[2]. In fact corporations suing people for defamation is such a big issue that there's even legislation to prevent it from being abused[3]
the CNBC link you provided even says that the guy who got sued for the review later won the case
further more to win the case the other company will have to prove that 1) the document were fake, and that we faked them, and 2) that it doesn't match their real pricing, which means sharing that pricing info with the court and the other party. sure boss, sue me, and tell everyone what your actual pricing structure is, on the record, and at risk of contempt of court. that could be far more damaging than than any actual blowback from people making up numbers on the internet.
hell, post how expensive my product is, so that when I discount it heavily to future customers they think they're getting a sweetheart deal. "oh that quote was for a customer who wanted several bespoke features added, so it was expensive for them. but it helped mature the platform :)"
Stop using words that makes it sounds like a crime. It’s a survey. Nobody is under any legal requirement to provide correct info.