I do have a preference for milestone/session based leveling but it's hard to implement in a cRPG the GM can't be at every session for. .
I do as well and no, it's not particularly hard to do either.
In fact, some of my all time favorites (Vampire Bloodlines come to mind) are computer games that used precisely a goal-based exp system.
Still, this has virtually nothing to do with having the systemic option to question the dead with a spell.
As already pointed the OP is conflating two different issues (having an exp reward system that let you leverage a murderhobo approach for maximum benefit and being able to interrogate corpses) and mistakenly assuming one thing is the cause for the other, when that's just not true.
He's just too hopelessly dense to realize this distinction even after this was pointed to him, so he chose to became gratuitously aggressive about it, instead.
