I mean sure, but take glassdoor with a huge grain of salt, people make up crap to post on there all the time.
It's certainly more truthful that marketing fluff pieces like this.
People still make up fiction and post it on there all. the. time. Keep that in mind.
Yes there will always be people that were fired writing things up as well as others just lying (competitors). Like you said, at some point when there is enough smoke you should expect a fire.
Interestingly, Peter Thiel starts his book Zero To One with a reference to the Anna Karenina principle by showing a corollary in business: "All happy companies are different, all unhappy companies are alike."