I didn't think of that. I thought horizontal, the top of a table or the like, with the time we see spent on the dowels.
What would be built with that? I can't think of anything that would have you facing the wide side of 2X4's joined like that. People will see where those are joined together ... I can't see it being strong enough for legs or framing.
My first thought? If I'm doing this I'm countersinking screws on the narrow end; filling with some Wood epoxy stuff I have, then staining to hide.