The NPCs aren't being "mechanically influenced" though. The player is stating an action. The DM is determining the outcome. If the DM is uncertain about the outcome and there's a meaningful consequence for failure, they call for an ability check. It's the action that is influencing the NPC, not the ability check. The ability check just determines whether the action is successful or not (since it was uncertain). Getting this concept straight in one's head is fundamental to understanding how the game works in my view. An ability check is not an action, nor an action an ability check.There's nothing at all wrong with "The PCs make their own decisions". Bravo. Preach it!
What makes me shake my head is that some of the same people pushing that stance are also pushing for PCs to retain the ability to use social skills/abilities to influence (if not outright force) NPCs' decisions, via the DM calling for a roll. To me this just sounds like trying to have one's cake and eat it too.
If "the PCs make their own decisions" is true then "the NPCs make their own decisions" should also be true. No rolling required unless someone - player or DM - wants to do a non-binding self-informative roll if truly uncertain how their character(s) would react.
Or (the much-worse option):
If the NPCs can be mechanically influenced/forced into certain decisions then the same should apply to PCs.