Remember, Wine is still beta software. Releases are snapshots. Unless we have a declared stable release there is no point in providing unstable updates for old unstable releases.
Of course anyone is free to maintain a few older wine versions, for the reasons stating above, and he is welcome to do so. However, I don't think we should spoil any existing resources on that.
I agree with you about fixing older snapshots. Somebody is this forum says that is possible that wine never comes to be finished. If you think for a moment, also MSWindows never was finished, always has bugs to fix, but developers learned to live with them and fix the applications to works with that bugs. I did several changes to my application to be compatible with wine, but if every time a new snapshot is released something is broken I can't support my application to be "compatible with Wine". May be we can vote to chose the best working snapshot as manteined where only critical bugfixes can be applied, so linux distributions can use it as supported and software developers can use it too as reference to release they software as "compatible with Wine". Also you can tell your customers to download "maintained version of wine" from winehq.org and be shure that your application will work. This maintained snapshot could be released every 6 month with a good regretion tests.
Of course you will say that Codeweavers already do that, but due to the price it's limited to expensive commercial applications, not for the small or simple ones that costs less than crossoveroffice.
Regards Christian