That's just pragmatic, although I am confused by what exactly you got out of do this if the shit you inherited from this patsy what shit you gave him in the first place - it is actually possible to use a lackey as a shield against the dislike of other characters? Because I can't see what other use you'd have gotten out of this.
Probably a bit like the old trick of inviting geriatric courtiers with no family to your court and giving them baronies to hold until they die. Ideally you even marry them off first to women past their prime so they have zero chance of having an heir.
The net effect is a part time caretaker for your baronies, stopping you from going over your demesne limit while still having (eventual) control over the baronies.