The problem is that Smalltalk community is too small; it's not surprising there isn't a 'critical mass' of users - not including Seaside, of course. I think it's enough (for now) just to keep up awareness of Magma, particularly in the Pharo community. (I'm really surprised those persistence discussions omitted Magma!)
As for lack of time - yes, I know the problem well :-(
Anyway, your work is greatly appreciated. I happily talk about Magma (and OODBs) whenever I get the chance!