You don't have to discuss it anymore, and feel not to respond to this. (Seriously.) As to your question of how many times of late has an umpire been wrong calling the mark? I'd say a fair few. That's why opinion is changing on it.
I was totally against it, initially, because the technology did not react well to the clay. But the technology has improved. On top of that, we've seen how electronic line-calling has worked, in general. Everyone agrees to accept it, and moves on with the result. It really just is time to apply it to clay, as well. I am as old-school as it gets, and I rather love to see the chair umpire leap down and inspect the lines. But it's starting to get a bit silly, at this point, the disparity between line-calling on clay vs. other surfaces.