Let me try to explain it for you then. Way, way back when people said that about 1080p, we were looking at 30-40" screens. 1080p was overkill. Now we're pushing up to 90", 1080p is pretty bad. You see, technology changes over time. Needs change over time as technology does.
No, I was talking about around 2007... at the time the smallest available 1080p HDTV were 46". Manufacturers weren't yet able to make them any smaller than that, the technology just wasn't there yet.
My point was that at the time I was researching getting a 46" HDTV -- people on forums and in stores said over and over that it was a waste of money to get 1080p and to just go with 720p. They said 1080p was overkill and pointless.
Now people are saying that Retina-resolution iMacs are pointless and I was simply pointing out the parallel I noticed. Obviously technology changes over time and I completely agree with you that it needs too. Which is why, bringing it back to my original post, I don't understand why people are often so against higher screen resolutions labeling them as "pointless".