It's interesting to consider all of this in full context of how Toshiro is framed in the scene.
The argument starts with Toshiro insisting that Marcille was wrong to revive Falin with black magic and that she should go back with him to face punishment from elvish society, then get their help in putting Falin to rest. Laios argues that they can actually help Falin, and that eating properly gives them the strength to pull it off, at which point Toshiro tries to shut Laios down by throwing his past frustrations in his face. When Laios eventually overpowers Toshiro, he attributes it to his party taking proper care of themselves, at which point Senshi shows up to offer Toshiro food. Meanwhile, Maizuru expresses frustration at Toshiro's behavior, and when Toshiro talks about his out-of-the-blue proposal to Falin, Mickbell questions why he would do something like that, while Chilchuck remarks that it's the kind of world he lives in.
Every part of Toshiro's position here comes across as antithetical to the protagonists and the quest we're following them on. Even other characters present don't seem to think much of his behavior here. And, while playing that antagonistic role, we see him imposing those social standards on someone who finds them confusing and alienating.
The result is that the primary lens through which the viewer is encouraged to see the scene is that of an autistic person being berated for not living up to a set of social standards, and in particular not meeting the standards of Japanese society. And while a Japanese audience might find it easier to understand why Toshiro thinks the way he does, the scene is very clear in sending the message that he is wrong and that, as previous comments noted, he's been stuck in a mindset that's hurting both him and Laios. The outcome of the fight suggests that Toshiro would benefit from learning to think more like Laios about food - and I think the audience is also meant to feel that Toshiro would benefit from learning to think more like Laios about people.
More than that, Toshiroās last line of that sceneāexpressing his envy of Laiosāsuggests that he, too, feels that he would benefit from learning to think more like Laios about people.