Mandatory Windows workstations correlate heavily with environments where you spend half the day watching your workstation sit unresponsive because it's doing one damn corporate-mandated background task or another. I wouldn't rule out an all-Windows place completely but I'd see it as an orangish flag demanding clarification. Software in general is bad and time-wasting enough as it is, I don't want all that extra frustration from a pile of poorly-conceived shitware using far more processor cycles and disk IO than my actual work does.