Why (neck design question)

[Neo Fender]

Not a "Neck Woods" question, so I'm posting here:

Why so much flat area that is away from the body?  On the Strat below (and most others I've seen), it, appears the neck's back contour could be continued at least another half inch or so toward the body (not completely, though - I understand that curvature has to be there to match the back contour with the neck pocket).

Maybe it's like a warning track that outfielders use.  "Whoa, I'm running out of neck here".

Anyway, just curious wondering if I'm overlooking something.

 

[AutoBat]

Stability at an important junction.
The amount of that did decrease approx 2 years ago.  My strat has an older neck that looks pretty much identical to your pic, whilst my VIP has a newer neck with a sharper transition.

 

[Cagey]

It's not a "warning track"; once you're playing up there you're already running into the pocket base, even if it's contoured. I agree with Autobat - it's more about structural stability. If you've ever played an SG, Melody Maker, Firebird, etc, you know what a limp noodle the neck joint is. You have tuning problems, sustain problems, tonal problems, breakage problems... the list is long. Shaping the neck heel like that doesn't affect playability, but it does enhance mechanical integrity.