In case anyone needed any proof that the reviews on Glassdoor are skewed, look no further than this article [paywalled] where Big Bleu isn't mentioned specifically, but the shady rigging of Glassdoor reviews by other companies is --
https://www.wsj.com/articles/companies-manipulate-glassdoor-by-inflating-rankings-and-pressuring-employees-11548171977
Indeed reviews are far more accurate of IBM and you don't need an account to read them.
Yea, the only way to get an accurate view of IBM from the outside is to look at the negative reviews on Glassdoor.
IBM reviews on Glassdoor were helpful when I left years ago. I learned to expect some negative reviews for companies I was considering. That's what real assessments look like.
Based on what I knew about IBM, I made it a rule to reject all companies with a large proportion of empty minded but glowing reviews. Worked great.
The fake reviews posted by IBM are easily identified....essentially any that are positive.