Not that hard to do, but not trivial either. Dunno why Adobe has chosen not to, so far. I can only assume it hasn't been high enough priority compared to other considerations - just guessing.
Hi Rob, As this feature has been requested 1000's of times since the 2nd Lightroom build, I'm sure its not because of the lack of this feature.
Either they don't read the feature request, Don't understand how to code this feature, or just don't care.
Honestly, I am hardly qualified to even guess - there are tons of bugs reported that would be easy to fix, but aren't, features that would be useful and easy enough to implement, but aren't. Things like focus points which seem like a no brainer but are never implemented - your guess is as good as mine..
But to be clear: focus points are different for different cameras, and are stored in proprietary metadata. - not impossible to get at, obviously, but requires some programming/maintenance..
Worth noting: Apple is shutting down their Aperture business. Yeah, they support focus points and all kinds of good stuff, but I guess Aperture isn't a real money-maker for them (lotsa maintenance work, but not a lot of revenue) - relatively small market.
Adobe has been working on Revel, and Lightroom Mobile.., instead of focus points (and bug fixes, and...) - my guess: that's where the money is, or where they think it is.
The difference between iPhoto and Aperture has been in the user interface, I suppose that by unifying the user interface in Photos, they are probably aiming for more cost effective solution across the con/pro-sumer field.
I've been sort of disappointed with the features supplied by Adobe for latest LR releases, maybe it's just me, but changing the platform looks very promising just now (I've used Lightroom since 1.0). If Photos delivers a better SDK, I might just tip over the edge.
I wrote a prototype of focus point plugin for my own cameras, but it gets really complicated to make a "end-user" version of such plugin, because Lightroom SDK provides absolutely no support for custom user interfaces. You cannot even overlay custom PNG graphics on top of photo view from a plugin, that feature is only available through user menus (things do get hairy when you try to script it using the menu items...)