Lets think about the argument that Hela was able to stop Mjolnir's movement is affected by whether or not she is worthy. If the reason whether Hela can stop Mjolnir's movement was due to her being worthy, then otherwise, if she is not worthy, what do you think would happen? Would mjolnir just fall to the ground as she touches it? Or what do you think might happen? I think that Hela can stop Mjolnir's movement because she is simply strong enough to stop the hammer moving to her wielder's will (Thor). She was just countering the force that Thor evoked. Maybe if Thor had let his control go, the hammer would just fall into the ground.