Philosophical Question: Would A Good God Perform Miracles?

Over at Thinking Christian, Tom Gilson discusses a New Atheist book The Case Against Miracles. In a recent post he discusses Chapter 2, "God Would Not Perform Miracles," contributed to the book by Matt McCormick. Gilson's response takes one possible approach; I'd take another. I'll mention that I don't have direct access to a copy of the original book and am responding based on a) quotes of the original material that appear in Gilson's post, and b) some comments that McCormick made in the comment section when he stopped by Gilson's blog.

I'm currently planning a 3-part response; this current post is the first:

1. (This post) Addressing the basic syllogism of McCormick's argument as gleaned from the comments by McCormick at Gilson's blog
2. (Tomorrow's post, already written; after I get this posted I plan to go pre-schedule that one) A response to the complaint "Why was Jesus hanging out at a party when he could have been healing lepers?" (paraphrased). I know this breaks my usual practice of posting only on weekends but I wanted to keep that topic separate from today's post without drawing out the series too long. 
3. Localized miracles and the scope of God's love (planned for next weekend's post)

So enough for the preliminaries. Based on McCormick's comments, it looks like his original argument runs roughly like this:

God wouldn't underachieve.
Localized miracles are an underachievement.
Therefore God wouldn't do miracles. 

Based other comments, he also seems to assert:

Someone who doesn't take this argument seriously is biased. 

But there's another option: someone who doesn't take this argument seriously because there's contrary evidence. There are miracles on record that, as far as I can tell, actually happened; so I do start with the view that we know the syllogism is missing something important because we have contrary data, and then the task is to spot where its assumptions diverge from known facts. (Note I stopped short of saying the syllogism is wrong. I think it has some underlying assumptions that are wrong but that doesn't come into the discussion immediately. It's easy to read into the syllogism things that it doesn't say, or to use it to prove an argument that it doesn't make. One step at a time.)

Note that it's possible for someone to accept McCormick's premises and still come away with the view that the miracles we have on record did in fact happen. McCormick merely argues that it's underachieving for the philosophers' omnimax God to do miracles. Even if we accept his premises, if we stipulate that the miracles with best documentation are recorded not for a hypothetical omnimax God but in the life of Jesus of Nazareth -- a local, flesh-and-blood human -- then the "underachieving" argument strikes me as inapplicable in the first place. It's hardly underachieving for a thirty-something Nazarene in Roman-occupied Judea to heal the sick, restore sight to the blind, and raise the dead. Sure, it leaves several follow-up conversations in need of happening, but one conversation at a time.

By the way I think the most applicable of McCormick's points for the real world is (roughly) "Why doesn't God just heal everyone?" That's planned for next weekend's post, after I clear away a couple of the conversations that need to happen first (this, and then tomorrow's).