How Can God’s Glory be “Diminished” in Calvinism?

Calvinist John Mac Arthur in his article, Why Every Calvinist Should be a PreMillennialist, writes: 

It is impossible to fully understand biblical teaching about the end times apart from understanding the future of Israel, the future of ethnic Jews in God’s plan. And if you don’t get Israel right, then your eschatology is confused and you cannot be blessed and you cannot give God appropriate glory and you cannot have a full hope for what lies ahead so that His glory is diminished, your joy and blessing are diminished as well (Bold emphasis mine).

I was under the impression that in Calvinism everything brings God glory.  He irresistibly controls all things in accordance with His secret eternal decree for the ultimate purpose of maximizing His own glory.  Even His decree to reprobate most of humanity is for the sake of bringing Himself maximum glory.  The sins He causes people to commit in accordance with His secret eternal decree are for His glory.  Everything is caused by Him in order to bring Him ultimate glory.  How then can someone diminish His glory if the presuppositions of Calvinism are true?  And how would MacArthur explain the fact that the one who supposedly diminishes God’s glory did so because God caused him or her to do so in accordance with an irresistible and unchangeable secret eternal decree?

So God causes some people to diminish His glory and this all for the sake of bringing Himself more glory?  Maybe it is something like how God irresistibly creates the pots for the purpose of talking back to the Potter and causes the “pots” to talk back to the Potter in Rom. 9:19, 20, and then rebukes them for talking back to the Potter.  But if diminishing God’s glory actually brings Him more glory, then why is MacArthur concerned that people will diminish God’s glory?  Wouldn’t he then be diminishing God’s glory by getting those who are diminishing God’s glory for the ultimate glory of God to stop diminishing God’s glory for the ultimate glory of God?  But then MacArthur’s act of diminishing God’s glory by stopping people from diminishing God’s glory for the ultimate glory of God would also bring ultimate glory to God anyway.  This stuff is really confusing.  Perhaps I have just misunderstood Calvinism.  Feel free to set me straight in the comments section if that is the case.

I actually agree with MacArthur that we can diminish God’s glory.  I think the Bible is clear on that point.  I just don’t see how one can hold to such a truth in light of the greater underlying presuppositions of Calvinism.  It is for this reason that I find Calvinism to be an impossible system to live out practically or even describe in normal language.  I am constantly reading statements like this by Calvinists that simply do not seem intelligible in light of Calvinist presuppositions.  Yet Calvinists continue to speak as they do because they actually live in a world that cannot comport with Calvinistic philosophy.  Maybe I am wrong or misunderstanding, but that is how I see it.  And if Calvinism is right and I am wrong then all of this (including my ignorance and misunderstanding of Calvinism) is just for the glory of God anyway in perfect accordance with an irresistible secret eternal decree.  With that in mind, I will try not to sweat it too much.