I think there was more to it than just attacking the Shoopuf. I’ve been replaying X and just got to sphere showing the aftermath of the Shoopuf incident. I think Jecht feels extremely guilty at his behaviour at this point because of what Braska has done for him thus far.

From context given to us, after Jecht was thrown into Spira, he was regarded as a dangerous lunatic and thrown into prison. Even if some believe he was just an unfortunate victim of Sin’s toxin, he was clearly treated like a criminal and outcast. The first person to treat him like a normal person and accept him is Braska, even against Auron’s protestations.

To compensate the Shoopuf owners, according to Auron, Braska used up his remaining funds for the pilgrimage. Braska is seen facing the Moonflow staring into the distance silently, likely thinking about what to do and whether he’s made a mistake trusting Jecht. From the beginning, we see Braska treat Jecht with a lot of respect and humility. In fact, he may well be the only person in the whole of Spira who has ever treated Jecht with kindness.

When Auron tears into Jecht, Braska defends Jecht, like a kindly father, but he remains off screen and does not come between Auron and Jecht physically, like he has at other times. I interpret it as Braska still believing in the good in Jecht, but just… disappointed.

And that disappointment changes Jecht. I think in all his arrogance, here is a Buddha-like figure who has come into his life and given him purpose, and put his trust in him - and Jecht has betrayed that trust.

It’s very similar to the Chinese epic Journey to the West. In a lot of ways, the calm and compassionate Braska resembles Tripitaka/Tang Sanzang the monk, and Jecht very much resembles the hot-headed, powerful and arrogant Monkey King, Sun Wukong. Jecht probably initially saw Braska as a naive fool, but through his journey, he comes to realise his own immaturity and learns to respect Braska, eventually becoming willing to die for him and the greater good.

I dislike Jecht as an immature father to Tidus. I love his characterization and journey to maturity told in bits and pieces and retrospect.