You're right, but I think the hard part is still to find people to bridge the gap between the system experts and domain experts.

An extreme example would be if you're trying to introduce a logistics management system in a shop that was exclusively using pen and paper. You'll need someone with a foot in both world to even get to the point where they can look at your models and/or documentation and say "yes, it matches the business".

Or one of the participant in the project will need to become that person (ideally the client, we can dream).