Trees, large dependency lists, and all sorts of microscopic task organization isn't something I feel is part of our core philosophy. I do think this is something the product (Maniphest, Workphlow) will be opinionated about with the understanding not all customers would like a simplistic task management application - and I think that is fine. I think there needs to be JIRAs in the world where some corporate structures dictation large ginormous workflows, and there isn't anything wrong with that. It's not the direction I see Maniphest taking, specifically in the near term.

Functionally as you describe it, soft means it's something you can do regardless of being dependant on another task. So this, like I think @btrahan eluded to, means it's not actually a dependency. Even if it is in your corporation, it's confusing enough that it's not something we'd upstream.