Sakura, though not as strong, is smart. They put her with Naruto and Sasuke so that they can balance out her weakness and she can, in turn, use her intelligence.
Because Sakura is better thats why.
Hinata was never planned to be a part of Team 7. Sakura, even if Kishimoto hadn't planned that far in advance, is a combination of Kushina and Rin and of course, Tsunade. Team 7 = the Sannin and Hinata is nothing like Tsunade in temper or physical power. Kaguya wasn't even a thought then and shouldn't be considered one now. Hinata is not the only female Hyuga, there is also Hanabi, but there is only one Sakura.
And THERE you have highlighted a mistake on kishis part.
He should have developed the character of Hanabi Hyuuga who did indeed share Tsunades fighting spirit.
Hinata being part of team 7 would have made more sense
Im confused because Hinata sucked ballz. There is actually a real reason, revealed by kishi himself would have saved you the effort. I also love how everyone thinks the initial purpose of kaguya having byakugan is more for hinata than the fact that we needed to know the origins of the byakugan as well as sharingan...