I've heard/read such reports about valve from various other people, including friends I trust saying so privately. He is an outlier in how vehement his criticis

I've heard/read such reports about valve from various other people, including friends I trust saying so privately. He is an outlier in how vehement his criticism is but is hardly the only one that throws that criticism at Valve (keep in mind workers face massive disincentives to do so publicly).