I had always suspected that Glassdoor would eventually succumb to this. Every metric is a gamed metric, after all. Why would Glassdoor be immune to this? Companies have very little to lose from bullying employees into leaving fake positive reviews. Yet they have much to lose from true negative reviews.

I have checked every workplace on Glassdoor prior to applying, taking things with a pinch of salt / applying some awareness of what reviews seem fake (like the famous split between loads of 1-star and loads of 5-star reviews, which tells you something is fishy, like loads of products on Amazon have).

I think I'll dial up the awareness for future purposes...shame.