Though disregarding Divine Simplicity might have problems due to how it is related to and defended by the use of Apophatic theology
The two are not entirely inseparable. You can have one without the other. Apophaticism sort of helps alleviate the ways in which DS comes into conflict with reason. Linguistically we are not equipped to discuss something which is considered "identical" to its attributes rather than simply having them, so you get bizarre unmeaningful sentences like "God is his goodness" or "God is Being Itself." It runs contrary to the grammatical format we use to discuss things, so we must go on discussing the divine in a way that ignores this (by necessity, due to it being incoherent) but keep an "asterisk" behind otherwise normal descriptions. Even in the face of blatantly composite elements like the trinity, some sophistry is conducted to insist that the three "persons" of the divine are not a separation or composition. They are all perfectly identical. Even as the Son cried out for the Father and asked him for answers, we must maintain that there is no real distinction between the Son and the Father. There's some kind of distinction, but it's not "real" (good luck figuring that one out). This is because God
must remain simple for the classical theists, as they largely co-opted Aristotelian notions of the prime mover to attempt to prove their religion, while also resolving the inherent dissonance between the conception of God that Aristotle actually provided, and the various ways in which an Abrahamic God contradicts those notions.
Apophaticism comes into play by noting that nothing we say about God captures his infinitude, and is thus just an "analogy" or "equivocation." This, again, comes into conflict with reason, so in practice it's takes the place of a similar "asterisk" to divine simplicity. We will go on discussing God as a normal thing, but maybe stop every 100 pages or so to remind the readers that when we say "God is good" we are making an analogy between the limited finite understanding of "goodness" that we see reflected in nature, and the infinite goodness that God is. We can only speak of God so far as our limited human intellect is capable of understanding him.
Of course, this too is largely meaningless. It does not provide any information about God nor is it capable of explaining what our words are failing to capture about him, but the assertion assists in portraying God as something supreme transcendent, and the self-rejection of our own language and reason allows us to swallow the pill of Divine Simplicity a bit more comfortably, since both language and reason would tell us it's nonsensical. Well, don't you see, it's just because we can't capture Gods infinite (but not exactly) essence (but not exactly). As DT points out, this violates the law of excluded middle.
So, we can reject one without the other, but my preference is to reject both. I don't think there's anything about them that places them above the more sensible and coherent conceptions of divinity.
