In Greek there is no capitalization. I understand your point about the article but it can be said that way and mean God Almighty. It's hard for me to believe that Paul wasn't alluding to John 12:40 and would refer to the devil as the "god" of this world. To believe that would be to necessarily accept that God and Satan are both blinding people at the same time. Not a tidy explanation. See the law of parsimony on this one, brother.
Would it be a big deal if I'm correct? What's at stake for you? I'm just curious.
What's at stake is what you would assert about God.
Further the article in the original together with what the passage agrees with John as to who is behind the darkness that is this present evil age is what allows for the lower case g as the understanding.
Believe me, I'm not into "agree with me or hit the highway." I don't need to be right. Its a sure way to end up, and stay, off-base.