Unfortunately, we’re dealing with a cohort of users who simply refuse to use anything other than their email interface to interact. Other use cases, no matter how compelling are of no interest to them.
As it happens I’ve just lost the battle entirely and the community is reverting to Google Groups. While much of this is simply the religious zeal for mailing lists of a small group, our fate was sealed by the lack of inline reply support and threading issues I’ve mentioned earlier.
I have participated in several threads on meta already around the topic of better email interactions; if there’s any traction I’ll do my best to help. These really seem like relatively trivial issues that could be resolved and make mailing list transitions much less painful.