Except that's not how you couched it in your initial post, which I responded to. You basically said it didn't matter because the President couldn't overturn Roe v. Wade. Look at your words below and your words above and see if they are consistent...
"I agree it is a silly position. But I don't see it as a dangerous one based on how little influence (essentially none) he would be able to exert to change anything. This is sort of like pro-choice folks who get up in arms about pro-life politicians, as if all they have to do if they achieve office is hit the off-switch on the legality of abortions. Not too long ago we had a pro-life president, and strong majorities of pro-life republicans in both houses, with a pretty even supreme court...and we still have Roe v Wade. This is an important issue...but it is a side issue in the context of a presidential election. Gay people have won acceptance through the slow turning of public opinion at a granular level and an intellectually consistent framework in the judicial system...that sort of thing does not reverse course based on a presidential election. I prefer to approach candidates based on their positions in areas where they will actually have some power to say how things will go."
The point is Carson's (and other's) position does matter, on gays, on abortion, on pretty much everything. They're applying for the position of leader of the free world. Their opinions on pretty much everything matters, especially since a huge percentage of Americans focus on the President substantially more than they focus on Senators/Reps/SCOUTS/etc. The fact that Ben Carson thinks being gay is a choice is something that should be discussed, and, in my opinion, held against him. He shouldn't be allowed to hide from this.