You just answered your own question. Everyone knew the Plus would be extremely supply restricted, so half an hour of lost sleep is a fair trade to get the phone weeks (if not months) before one would by otherwise waiting until this morning.
Why was this a known thing, that the Plus would be so limited? I wasn't keeping up.
Anyway, I preordered my plus for delivery in October. I'm still a bit skeptical of the size but we'll see.