Because that way we can sell you TWO software packages while we laugh at you.
Story of my life lately. The joys of juggling 3 different versions of Microsoft office while migrating from MOSS 2007 to 2010
To be fair, their licensing structure usually allows you to use any previous version of the product if you own the current version. Although where you get the media from ...
but can you have both packages active? I thought you had to have two licenses to have both packages active... and who wants to keep uninstalling and uninstalling software?
Yeah I would need both now, as we are transitioning from MOSS 2007 to 2010. Eventually I will only need 2010.
as I understand it you can have both installed and activated but you may only use one at a time. That's how it used to work but things may have changed ...