Wait do you mean your experience working for companies that mandate Windows, or your experience listening to anecdotes from people who've worked at said companies?
Both. But I don't give much credence to internet anecdotes -- they are untrustworthy. Close-friend anecdotes who give lots of details are a big part of my impression.
It might be one of those false-positive effects.
e.g.
Few windows shops are Initech, but all Initechs run Windows, therefore to avoid Initech you could avoid Windows.
There are probably other heuristics with fewer false positives, but anyway I'm just saying.
