Why not deism?

[GrandizerII]

"God exists" in this context means a maximally great being exists, one that is omnipotent, omniscient, morally perfect, and necessarily so in all possible worlds. God is not simply the ground of all existence here.

https://www.iep.utm.edu/ont-arg/

Visit the link above and scroll down to the bit about Platinga and his MOA.

What makes those things greatest?   If say, I value malevolence, I may come up with an entirely different set of characteristics.  What are these criteria other than an expression of our own desires?

Yeah, that's another fault with the argument. And in fact someone actually made a blog post (along with a video) about something along that lines:

http://counterapologist.blogspot.com/201...ument.html

So here’s the syllogism:

A being has maximal depravity in a given possible world W if and only if it is omnipotent, omniscient and wholly evil in W; and
A being has maximal evilness if it has maximal depravity in every possible world.
It is possible that there is a being that has maximal evilness. (Premise)
Therefore, possibly, it is necessarily true that an omniscient, omnipotent, and perfectly evil being exists.
Therefore, (by axiom S5) it is necessarily true that an omniscient, omnipotent and perfectly evil being exists.
Therefore, an omniscient, omnipotent and perfectly evil being exists.