I’m not sure why he has an, "if" in his statement. The Bible doesn't say signs and wonders have stopped. Just like it doesn't say teaching, helps or administrations have stopped. In fact, all these gifts are mentioned alongside one another in 1 Corinthians 12:28.
So the premise can’t be verified with Scripture.
As far as the rest of the claim: Admittedly, it does sound reasonable to an extent. However, as I often try to remind my audience—-something sounding reasonable is a subjective metric. What makes sense to one person, may not make sense to another. So using, “persuasive arguments” as a measuring stick for what’s true and what isn’t, is going to yield a wide variety of conflicting conclusions.
The fact is, God never said the gifts would only be given to, “the purest, most faithful sound teachers of the Word.” They're not given as you, or I, or even John MacArthur wills. The Bible says they are given as He wills (1 Cor 12:11).
Aside from the absence in Scripture, what makes it even harder to justify this quote is the fact that we see Paul rebuking the Galatians for being bewitched while also mentioning that God is working miracles among them (Galatians 3:1-5). Similarly, the Corinthians are commonly believed to have had many demonstrations of the gifts of the Spirit yet had to be told that no one who is prophesying could call Jesus accursed. They also required discipline for their pride and lack of mourning concerning sexual immorality (1Cor 12:3, 5:1-2). Imagine having the gifts of the Spirit at work among a congregation that is simultaneously okay with a kind of adultery that isn’t even named among heathens.
God doesn’t always do things the way we think He should.
Now, sound doctrine is obviously of the utmost importance. But I’m not sure how much of a connection there is between it, and miracles. Unless Mr. MacArthur is prophesying, here (which would seem to conflict with the claim itself)—-His opinion is just one more drop in the ocean of unsubstantiated claims made by Christians concerning the nature of God.
All of that aside, I suspect that a statement like John’s may speak to a deeper ideology among many Christians. Namely, “If God were to use anybody, it would be people like me. He isn’t using me, therefore He’s not using anybody.”