The whole standing reach and vert leap is a bit over rated.
This. Combine measurements are basically worthless. There's a reason most NBA execs and chief scouts don't even bother to attend the draft combines anymore. Not only are they not reliable measures of performance, but there are too many weird factors that can affect a player's measurements on that day. They are really only good for general benchmarks and relative comparisons rather than any absolute truth about a player's ability.
Vertical leap especially people read too much into. It's just a vague way to call a player athletic.
Why would they attend? They can get the numbers without watching guys. It would be pointless to watch the measurements being made, even though the measurements are very useful for decision making.
I don't understand the logic of the initial post. Comparing personal measurements with Zeller's? Remember the comment about Elton Brand that he has no neck? Height is a less useful stat than standing reach. Obviously, no state is solely responsible for the quality of a player. But if you think height is useful, standing reach is definitely useful since it measures something that matters more than how high your skull is -- how high your hand can go. Standing reach cannot be derived just from someone's height. That is the whole reason they measure it separately. It matters where your shoulders are.
Standing reach matters because you usually only get one chance to jump when defending, especially when man-to-man. If you have the better reach, you can interfere with a shot without jumping, meaning you also have a better chance to box your man out. You also are less likely to bite on pump fakes. Height matters in as much as it has a correlation with standing reach.