It's like when you see a dozen Glassdoor reviews for an employer where the only recommendation to management is to "keep doing what you're doing" and that any complaints are "sour grapes" or from employees who can't handle "growing pains".
Any positive glassdoor post should be suspect. You generally visit glassdoor for three reasons.
1. You are researching a company.
2. You own or work in hr at a company or have been told to post a review by management.
3. You are angry/unhappy at your current role or that you were let go. You go on to warn others / get even.
Rare is the person who is working a company and is happy who decides to visit glassdoor and tell everyone how happy they are. Have you done this? Know anyone who would follow this chain of events?
Glassdoor asks to leave a review for your current company or share your pay before looking up in detail about other companies. I wrote a review about my current company just for this reason but it was a honest review and not overly positive etc.