The author certainly has done a lot of research about mathematics and the history of mathematics in order to write it, and I suspect that an audience member who is not similarly an expert in both will miss many of the plot twists and cultural references. Consider the following review in the New York Times:

Having now read the play myself (although I have never seen it), I must say that I disagree. It seems to me that the author most certainly understands the math. For instance, from the beginning of the play, Vazsonyi's daughter Hypatia is playing with the number 2⁶⁷-1. First she computes it by raising two to this large power and subtracting one. Then she also computes it as a product: 193,707,721 x 761,838,257,287. To most audience members, these scribbles that she writes without comment probably just look like "some math". But, it becomes quite important to the plot when one of the mathematicians at this conference is presenting his talk in which he will demonstrate the existence of an odd perfect number. This is a dramatic moment for the speaker and the audience because they consider this to be quite a significant discovery. The proof depends on the primality of the number 2⁶⁷-1, from the sequence of prime numbers discovered by Mersenne. However, Moses notices Hypatia's factorization of this number written on the wall, thus destroying the speaker's proof and leading to his suicide! In fact, Mersenne did mistakenly claim that 2⁶⁷-1 (abbreviated as M67) was prime, and this is connected to the theory of perfect numbers. Quoting Wikipedia:

Another source of tension in the play is the growing concern about paradoxes and the possibility of undecidable propositions in mathematics, foreshadowing the discoveries of Kurt Gödel that the educated audience member realizes are only 20 years away (since the play takes place in 1911). Other points that may be lost on most viewers are the inside-jokes hidden in the names of some of the characters: Moses' daughters (Sophie and Hypatia) and especially the name of the hotel proprietress (Hilbert).

So, I think the play must be thought of as being more meaningful than NYT Reviewer Weber gives it credit for. Still, I must admit, I am not exactly sure what it is trying to say either. It does not seem to me that it is ridiculing the mathematicians as being pompous or criticizing them for thinking that math is valuable. Certainly, the limits of the powers of math are a factor in the play, but not so much that it overshadows the value and beauty of the math. Consider, for example, this soliloquy from Hypatia towards the end of the play:

So, then, what is the play about? It seems much more about the emotions and human interactions at this beachside conference. The romances (illicit and otherwise), the marital difficulties, the egotism, the temptation to plagiarize. Perhaps the height of the dramatic tension occurs in the scene where people are arguing over the ownership of the notebooks in which the Five Hysterical Girls theorem is proved. My biggest complaint is that this seems too derivative of Auburn's Proof. I am not aware of any such argument occurring in the actual history of mathematics but, just like the math conference pill popping which occurs here and in Proof, it is becoming a standard part of mathematical fiction.

I would love to see this play performed sometime. Perhaps then I would even feel that I understand the point. Until then, I can only say that Groff has really included some interesting mathematics in a play reminiscent of Proof and Arcadia...and that's not bad company to be in at all!

Another review of the play can be found at http://www.curtainup.com/hystericalgirls.html