I agree, this is a serious problem. I see it all the time. But not EVERYONE is like this.
I have a deep understanding of Windows technologies (since NT4, AD, Exchange 2003 through 2008, SQL Server and more) as well as Linux (been using it since 1995), FreeBSD (1993), OpenBSD, Solaris, and more and most opensource technologies like MySQL, Sendmail, Postfix, Exim, Courier, Dovecot, Bind, etc. Hell, even stuff like Oracle.
I like to use the right technology for the job. Even though I _prefer_ Linux or Unix based solutions, I will use the right tool for the job. Sometimes FreeBSD or Solaris is better (such as when ZFS is concerned.) Sometimes Windows is the better solution (granted, not often. Mostly just as AD for windows desktops.)
Yeah. We exist. We're called Senior Systems Engineers and Systems Architects. There might be a short supply of us, though. My skills got me a visa and I now live in the SF Bay Area because my employer spent over a year looking for a local and couldn't find one that was any fucking good.