I would call it more of a design limit rather than a flaw. If AEC engineering says that is the way it was engineered, then their logic follows suit. If important things would start to break at loads higher than the hydraulics can handle, then consider it as a way the aircraft is talking to you, trying to tell you that you've effectively found one corner of the flight envelope. If anyone is routinely experiencing it, then I'd have to say they need to re-evaluate the aircraft they require to do their mission.
There are many single-point failures in a helicopter, this "feature," intentional or not, helps keep pilots from finding any of them.
FWIW, depending on the design criteria, dual hydraulic pumps may only provide redundancy, not increased hydraulic force. The choice ultimately lies with designers.