Not really true. Windows has copied loads of stuff from Linux GUIs over the years. I began to notice this around Windows Vista.
> A lack of bread and butter 1st class "business" apps - you know, office. OpenOffice is fine, IF you are ok with the janky ui and no one knowing how it works
This is valid. Shouldn't be so bad today with web apps being a thing.
> lack of open source exchange type mail/cal/etc server and outlook-like client). Holy fudge, I tried to get this going and people just crapped on me for suggesting it.
Yeah, because MS locks other mail clients out. Thunderbird is an excellent email client. Outlook is some proprietary business messaging thing that also happens to support email (badly).