Also, as for having a longer Phase 4 beta, there is a rather massive issue with that: Namely all those shipments of pre-order disks likely already loaded and being shipped out. If this were download only, pushing back the release would have simply meant not turning on the open downloads or issuing keys openly. Soon, FFXIV will be sitting on shelves at retailers globally, and holding that off means either forcing retailers to sequester copies at their storage cost, selling copies of a totally non-working game, or worse case, recalling all of it and reshipping it at massive cost.
The reality is that launch is just too close. If this had happened in P3, pushing launch would be easy. The product would still be in SE's hands, and they just call and resend the ship orders, pay whatever penalty for short-notice cancellation, and replan the launch. It didn't. So here we are.