Necessity is not evidence

[Neo-Scholastic]

What's missing here is an understanding of how specific arguments sit within the context of a larger multifaceted philosophy. The most one can ask for from a philosophy is that it conforms to experience and has a high degree of internal consistency. I cannot think of anything that is absolutely conclusive. From the sound of it Platinga's argument is consistent with a possible worlds ontology. My understanding of modal logic is slim at best so I must defer to those who have a better grasp of it. In general ontological arguments fail to convince, not because they are flawed, but because they only apply within an irrealist framework.