Also, it's not necessarily stupid to give titles away to lazy people. If your land is known for political turmoil, you might just was the lazy guy wielding all the power you don't wield yourself, to lower the chances of your appointee later using that power against you.
The economical performance of the realm can easily come second to just keeping power. Production isn't all that important when the threat comes from within.
This was another thing I was thinking; effective land-management can create rivals. A wise and self-interested ruler might want to think twice before appointing a very effective, strong, possibly ambitious duke, unless there are existential threats from the outside.
