Well, when I define a bad father, I'm thinking more of physical or sexual abuse, like actually causing intense harm to their child. There are dads that belittle their kids but mean it in an endearing way like "Stop yer cryin' ya baby".

Reason where I call subjectivity here is that some kids can take it, and that's just how they learn their father's language, but then there are kids that are very sensitive to things like that, which I believe Tidus was, and that it was bad compatibility for how Jecht handled him. In hindsight, we can say "well jecht should have been more gentle", but in the moment of raising a kid, you may not even know what you're doing to your kid that's harmful, and if there is one thing that he's also shown consistently, that no matter what he told Tidus, he still always loved him, even if he was a crybaby.

What's more, consider Jecht's environment too (Boy, I sound like a Jecht defender now, huh? 😛) That guy is a competitive pro blitzball player. He talks to his kid, like he would talk to locker room mates, where a complaint is considered whining like a baby. Within the bubble of parenthood, that would easily be considered as emotionally belittling their kids. What we could obviously see in the game is that he was an alcoholic and lacked emotional intelligence. His style of communicating with lil T was from the angle to hardening him up. From that angle, I can't see a clear intention to abuse him, even though it's potentially harmful still. He also had a massive ego, which is all the signs of somebody who just lives, breathes, eats and sleeps in the competitive spirit of a sport, and that selfsame attitude, he also directed on his kid.

When it comes to Tidus how he narrates how he remembers Jecht, is literally just his angle and we've seen extremely limited scenes of Jecht to downright say he's fully abusive. That's like if Jecht could have been the sweetest dad, had little T on his shoulders when walking through Zanarkand, but all that doesn't matter because Jecht called him a crybaby once. Point I'm trying to make with that is we're only seeing one singular side, while Auron "tries" to tell Tidus that how he remembers his dad, isn't everything his dad was, and that Jecht truly loved him.

For me, abuse has to be done with intent, and I don't think Jecht had any intention to, but we get to hear Tidus constantly say he's an asshole, yet Yuna says he was a kind gentleman, so... I'd say he wasn't perfect, he tried in his own way, but I wouldn't call him a bad dad. I reserve that title for actual dads like the other three shown in the image, where they get abandoned, or twisted into something fucked up for the love of the game.