The old software didn't perform or scale well as SDN's users grew, and database errors/failures and downtime were becoming a problem. This is the reason for the new forum software. Unfortunately doing nothing wasn't really an option.
I suspect in time the format will be tweaked a bit. It does take some getting used to. A number of bugs and features are being worked on in a prioritized way. The feel is different but the same functionality will be here in time.