One of the ugly rumors floating around out there, to generate fear and doubt from obtaining a dual OS certification. Whoever started this rumor may have possibly scared people away from getting certified if they already had placed the time and effort into a MCSE. After all, there are more tests to take for an MCSE then for some of the Linux Certs.
A major reason this rumor was started was to show how evil Bill was and how they were trying to run Linux out of exsistence. If a network admin had knowledge and understanding of both systesm, why would he choose the more expensive one?
In fact, let me share my own personal experiences. I was starting to look into Linux certification for my current job and also as a way to better understand and learn a different, and new to me, operating system.
I started looking at CompTIA's Linux + and sent the folks there a question about this and also sent a note to Microsoft and asked them the same question. "Will a Linux certification void my MS certs?"
Here are the responses, first from Microsoft:
Obtaining another certification, whether it is Linux, CompTIA, etc, it will not "Null" your MCP certification or MCSE.
and from CompTIA:
Thank you for your email. No this is not true on CompTIA's part.
Thus it was all FUD and unfounded internet rumor