In enterprise environments msi installer is mandatory. MSI allows software deployment over enterprise network with only a few clicks. Also, with MSI features as software publishing are available.
Perhaps a corporate sponsor could pay the author to (or pay for the software to) repackage as an MSI. Or a third-party with access to that packaging software could make an MSI available as a way of helping the project. It hardly seems "mandatory" for the developer to do this for free on his own time, just to cater to money-grubbing enterprises deploying his software at no cost, unless they're also supporting his efforts somehow.
It also doesn't seem out of the question for a savvy sysadmin to create an MSI him/herself using instructions here (from a quick web search): http://support.microsoft.com/kb/257718
Perhaps a corporate sponsor could pay the author to (or pay for the software to) repackage as an MSI. Or a third-party with access to that packaging software could make an MSI available as a way of helping the project. It hardly seems "mandatory" for the developer to do this for free on his own time, just to cater to money-grubbing enterprises deploying his software at no cost, unless they're also supporting his efforts somehow.
It also doesn't seem out of the question for a savvy sysadmin to create an MSI him/herself using instructions here (from a quick web search): http://support.microsoft.com/kb/257718
or here: http://searchwindowsserver.techtarget.com/tip/How-to-create-your-own-MSI-file-to-deploy-applications?Offer=SUN040106 (full article text is there, in spite of message about free membership).