Really unsure with this one, but I simply cannot get it out of my mind that he has a chance.
What's the Work?
Luca is a Pixar animated movie released in 2020, that tells the story of a marine, merman like creature of same name living in italian rivera. Despite growing up, like the rest of his kind, dead afraid of land monsters, that is, humans, he desires to explore the surface and the human world. After meeting a fellow sea monster named Alberto, with similar ambitions, the two of them venture into the small town of Portorosso, with their innate ability of turning into humans once they're dry, while attempting to hide their identities, ending up learning a lot of things about friendship, and about themselves. (Source: My own Luca proposal)
Who is him?
He is a simple, silent and very serious but overrall nice fisherman of Portorosso. Father of Giulia, he takes upon himself the task to have Luca and Alberto live in his house in the summer, as they are Giulia's teammates in the yearly Portorosso Cup. A very stern and serious figure, he eventually shows himself to mellow out, especially to Alberto, a lonely kids besides his friendship with Luca, that looks up to him as a paternal figure.
He is also the deuteragonist of the sequel short Ciao Alberto, where he and his now adopted son Alberto, one of the protagonists of the original film, solidify their relationship through various mundane (attemped, on Alberto's part) tasks.
What does he do?
Well, he is pretty loving to his daughter, who seems to love him and her mother equally and have no bitterness about the separation at all. He is cordial to Luca and Alberto, though his seriousness put them off at first, and they're scared of becoming targets of Massimo's fishing.
He has Alberto and Luca fish with him, and scares Alberto with a story about a sea monster biting his arm off, before showing it to be a joke. He subtly comes to be fond of Giulia's friends and their antics, particularly Alberto. When they come home WITHOUT Alberto, he immediatelly goes looking for him, even when Luca warns him Alberto may not want to be found, because "you never know".
In the climax, he supports his daughter with a handmande "Go Giulia!" sign. In the end, when Giulia crashes her bike to save Luca and Alberto from Ercole, and both of them, in their sea monster forms, go check for her safety, he grabs his harpoon and goes to defend his daughter from what he believes are monsters. When he understand the situation, he takes the side of the kids, and declare Alberto and Luca winners of the race. As Luca's parents and two old ladies also reveal their sea monster forms, and the town mostly sides with the kids, a few fishermen still show agreesive intentions and have their harpoons at hand, but a single glare from Massimo makes them, begrudgingly, back down.
Corrupting Qualities?
Well, first, he is serious I wouldn't say he is a game changer or anything. Not only the movie has dark moments totally unrelated to him, he has many lighthearted bits (his seriousness itself is kinda over the top and played for comedy), like him being introduced singing opera and eating pasta like Luca and Alberto after looking to make sure no one is watching, only to be caught by Machiavelli, his cat.
As for his sea monster "xenophobia", he is simply hunting what he thinks is a particularly big fish. He also thinks they're dangerous, rushing to protect Giulia when Luca and Alberto go near her. He is very quick to realize he misjudged the situation and protect the boys, showing there was never actual hate; just a hunter instinct and understandable wariness.
And while he spends a majoritiy of Ciao Alberto kinda distant from his adopted son, only showing disappointed and annoyance when he fumbes over a task, he simply does not know how to be a parent, as Giulia only spends her summers with him. He wants to know Alberto and just doesn't know how. When he gets angry over the boy accidentslly setting the boat on fire, not only it is understandable, but he stops Alberto from going away from home in self loathing, and tells a story about him and his father, similar to the situation they had, and asks to rebuild the boat together. They end the short helping each other rebuild the boat, laughing and telling each other stories, showing he got over his shortcomings to be a loving and present parent.
Admirable Standarts?
Surprisingly, he passes with ease. You see, even when Giulia stood up for the boys, Ercole succeeded in having most of the population fear them. It is only when Massimo takes the front, and declares them winners of the race, that everybody calms down, think things through, and accept them. Then, we have the handful of fishermen who still harbored harpoons and clearly had agressive intent towards the boys and sea monsters in general, but Massimo had them back down with a glare.
The kids may be admirable on their own, but Massimo is the reason Portorosso is safe at all for them, and any other sea monsters, playing a big part in having the overrall public give them the benefit of the doubt, and intimidating the few still murderous ones into not doing anything funny. Portorosso is a safe haven for the sea folk? Thank Massimo for that.
Veredict?
Even in a slice of life movie, and not being a main protagonist or anything, I believe his actions make him worthy of the category. A weak yes.