What an excellent write-up, and very entertaining at that.

I suspect that most devs will prefer the local maximum that traits are. Perhaps with a bit more help to ensure there's only ever one implementation of a given trait -- think of a trait registry. One might still allow multiple implementations, but with one single one chosen at final link-edit time or, if linking dynamically, at run time. To support something like that the registrations in the trait registry would have to be exacting as to each trait's semantics. A registry has its own cost: friction, and someone has to be a registrar, and registration might have a cost. But a registry has its advantages, and one could have namespaced traits, too, to enable multiple registries/registrars. Registries might feel like a hack, but so what, compared to the problems with implicits, they might be worthwhile.