I see a false dichotomy here.
Yes, obviously, if the Lords of the realm are totally apathetic and refuse to get off their butts and ever do anything with food, the realm should have major problems. (I would note that it's unlikely that the realm would die even in this situation unless they're in a serious war at the same time. They'll just have some seriously annoying starvation issues in the cities they can't get enough food to. The rurals, in particular, will all be just fine no matter how much food is rotting in their storehouses.)
But a) as has been repeatedly stated here, the problem isn't so much that Lords aren't moving food, it's that they find moving food dead boring and it's killing their enjoyment of the game, and b) even in those cases where Lords are, in fact, refusing to move food, it's almost never at a level that's likely to cause even a single city to go rogue. It's just enough to cause frustration and anger. And most of that frustration and anger is at the system, which is attempting to force a level of engagement that just isn't there.
And finally, Tom, you seem to have forgotten one major point in all this: Lords are no longer the respected and valued members of realms that they used to be. Lords are nearly half of every realm on every continent. No continent currently has even 3 nobles per non-rogue region. This means that if Lord Goodfornothing wants to sit around doing nothing with his region, there's a very good chance that the realm's choices are either put up with it, or lose the region entirely.
Realms very rarely have a choice these days between "good candidate" and "bad candidate" for a Lordship. They have "whoever says he's willing to try". So complaining that players aren't doing it right, and they should be happy with a system that demands they do things they find "not-fun"....yeah, that's a recipe for no more BattleMaster.
insert segue into player density here
