Hinami is talented at game even before she plays Atafami, she's just so naturally good and I think it's not a stretch to say there's a person like that. Even Tomozaki admits that Hinami is scary in the way her growth is much faster than his own pace. As for a truly top-tier gamer, if I remember correctly. Hinami herself is not confident to take her skill to pro-level as told in Volume 8. This is her flaw, her moves in real life is too calculated and she most likely considered the factor that reaching the level of pro-player is not only difficult, but she would have to sacrifice her future plan like studying, track club, and social activities (in fact Hinami plans to go to Tokyo Uni and become a banker or something like that). Her goal is to defeat "Tomozaki" in the game and I wouldn't be surprised if she retires after she achieved that. However, Tomozaki, unlike Hinami, wants to live his life to the fullest and go after what he really wants. He declared that he wants to go Pro after being defeated by a real pro-player.
This is the difference between Tomozaki and Hinami, and that's the point of the first three volumes which act as the prologue of the series. Tomozaki's goal in life is to make Hinami understands the joy of playing the game of life. Tomozaki thinks what's important is not just being an overachiever like Hinami, but doing what he truly wants in life. So when Hinami gives her a quest that against his principle, he refused to do that.
Also, if you get irked by Hinami every single time, man... you're missing so much. What makes the series truly shines is not just Tomozaki and Hinami, but also the other characters like Kikuchi, Mimimi, Tama-chan, Izumi, Mizusawa, Nakamura and others. Like how Tomozaki slowly patched his friendship with Nakamura, how he helped Izumi to get close to Nakamura, how Mimimi respects Tomozaki and Tama-chan, also Mizusawa is pretty cool guy. He's inspired by Tomozaki and confessed to Hinami, even though he knew he would be turned down, he still did it because that's what he wants. Kikuchi is also moved by Tomozaki because she sees him as someone who's able to change and express himself in genuine way.
The point of the series is do what you want in life, while also improving your skill. Make yourself a positive energy for people around you, nothing will change if you just wait and wait, afraid of failure, and not making action.
If you still don't like it, maybe you can go on and read other series instead of accusing the author of bad writing when in fact, what you felt about certain characters is truly intended by the author.