The devs don't take an issue with the ticket being filed. They're irritated by one particular reply which sounds like "My million dollar product depends on this bug fix. Please do that for me". MS isn't offering a solution. They're asking for one.
To be fair MS offers an amount for the fix. Most companies just bully the devs instead. However, I don't think it's quite fair (though legal) to offer one time payments for a core library that they use.
The kernel isn't a place to play politics. You can't just yank a component out like that on short notice, even if it has such a horrible story attached to it.
Back then, ReiserFS was mildly popular and its use would have been widespread (that includes me). The users of ReiserFS and probably even the other kernel devs had no idea that Hans Reiser was capable of such a crime. Infact, he was known as a computer prodigy back then.
There are plenty of users who don't have the luxury of migrating data on a short notice to a different filesystem. Disabling the filesystem would have left them high and dry. That's why the devs gave it a long deprecation period.