While it might be true that AbuseFilter can benefit from more and more active maintenance, removing the feature from our sites would be a total disaster with regards to anti vandalism and anti abuse prevention. As steward, not only I can vouch for its effectiveness on local wikis but also elsewhere with the global AbuseFilters. I'd like to join @MusikAnimal @Xaosflux and @Bawolff on their statements that AbuseFilter is a critical tool. On the other hand, yes, this tool coud use some more love, and I'd like to propose that internally WMF creates a team to maintain and improve this extension. Sorry if it sounds disrespectful but this is a much much more needed feature than Flow/Structured Discussions or other kinds of projects which have received funds and time from WMF and its staff. WMF should be funding a team of developers to take care of extensions such as AbuseFilter and CheckUser. Thanks.
Topic on Talk:Code stewardship reviews/Feedback solicitation/AbuseFilter
As I said above, I don't think we should be worried about it being removed, rather establishing sufficient resources for it in the long-term.
But anyway I wanted to say that I 100% agree that AbuseFilter is more important than Structured Discussions, or frankly many of the highly-funded projects. AbuseFilter is very much behind-the-scenes, so people don't realize how critical it is. If it were removed (again I don't think it will be), I firmly believe the wiki would be reduced to garbage, probably within a matter of weeks.
+1 and piling on that this software component should be treated as a critical service for WMF hosted wiki's, having volunteers trying to clean up mess client-side (such as via running bots) would not be able to keep up with issues that the edit filter can handle server-side.