I'm not sure it answers the problem at all, so I'm not sure how to make the evaluation that it's "more plausible" than some other alternative. Theoretically, in some possible worlds I accept Christ and in other possible worlds I don't. On Molinism, if the actual world happens to be one of the possible worlds where I don't accept Christ, it's hard to see how my lack of acceptance (or even a willingly made wrong choice) is somehow my responsibility and so I fail to see how I'm morally culpable. The choice of actual-world-selection is God's choice - he could have selected the actual world to be one of the possible worlds where I do accept Christ. If in fact he didn't, and so I don't accept Christ, the problem is one of God's choice in actual-world-selection.On Molinism, God is not simply a passive observer of activity, he takes an active role and makes an active decision that is a pre-condition for all outcomes observed in the actual world. On Molinism, it seems human freedom has a critical and decisive limitation that is instead deferred to God, namely, in selection from among possible worlds.
WLC believes that God selects the "best" possible world which he takes to mean that God solves an objective function where he minimizes and maximizes under constraints. God maximizes souls saved and minimizes souls lost under the constraints of human freedom. So God's actual-world-selection process has nothing at all to do with the merits of my action and is hardly a decision that deals with giving people justice (assuming a utilitarian view of justice is a wrong account).
When the lost soul stands before the final judgment, he could argue that he would have accepted Christ had God selected a different possible world and that God's world-selection had nothing to do with the individual merits of the case. Thus, God has treated him unfairly. And it looks to me to be a pretty good argument.
The same is the case for the creation of evil. God knows which possible worlds result in the existence of evil and creates one anyway. It seems that he has a critical role in the existence of evil - he knows which environments bring about evil and creates one of them. I'm not sure how Molinism escapes these issues or somehow becomes "more plausible" than some alternative.