Yeah you got a point there, Sakura is like the most "human-like" character in the anime, Kishi probably didn't even want her to learn alot about those powerful genjutsu type moves, maybe he just wanted her to be like... batman for example. Smart and great at fighting(taijutsu) but without any strange powers and/or abilities. Sakura is pretty much just an average ninja, but I hope that she at least learns a few more genjutsu typed moves, even though she may not even be able to learn more about genjutsu.
Not to say her learning some using genjutsu would be interesting, I'd love to see her become more useful in the series rather than just crying over the other characters. Now granted, she's the "human" in a bunch of "mutants" in a way, so she can't really do a whole lot. At this point, can you imagine Sakura fighting like Rock Lee or busting out jutsus like Sasuke or showing high-class intelligence like Shikamaru?
Well, the intelligence thing needs to come back into play. Early in part one, she showed so much promise of growing into a strong female character for the series, because of her smarts. Remember, she passed the exam without cheating. It's small things like that which makes her an ideal character.
Combine that and her unusual strength (or moreso 100% chakra control) she could be a real interest character if given some time to develop.
When the rescue Gaara arc came by an she was fighting with Sasori, I was actually excited because it showed how much she's grown. Unfortunately, after that she went back to being in the background. Such a shame. Then again, still better than how Kishi's treated Tenten.