I'm really surprised people are sympathetic to the shadow druids. For one thing, the ones we fight are pathetically weak. For another, they seem to have no interest in being your ally. There's nothing in it for them.
We still don't know if the evil path even exists per se. We have evil choices among a narrative path, but not different narrative paths. This could be a consequence of simply keeping enough content unreleased for Act 1 to feel "fresh" like Larian promised.
I'm not sure where to start with my own criticism. There's too many unknowns.
However, since the druids aren't an ally, I doubt you'll get to ally shadow druids this soon. If they're relevant, we encounter them again. If not, this was one of few scant nods to their existence. Whatever happens to the druids, our only benefit from that encounter is Halsin and some magic items (unless siding with goblins).