I hate to try and be contentious, but:
BA don’t offer priority luggage to Y pax. I’ve had this as a gold. I’m sure some premium cabin folk would argue that too many bags tagged priority kind of negates the service.
I may be wrong (often am), but isn’t baggage delivery undertaken by airport baggage handlers and not BA, so a delay in the baggage arrival at SIN may not really be entirely the fault of BA? (Shocked it took an hour as SIN has always been as near as perfect on this front when I’ve travelled through).
Possibly the 2 x curry option was a one off / not the norm.
I’m not sure many would argue BA are better than SQ, but just trying to offer a bit of balance. As you say though, BA were full in the back of the bus, and while they continue to enjoy this it is hard to see why they would change their ways.