In the comics Thanos never had any kind of anti-hero goal in the comics and that’s important because the people in the comics as a result didn’t try to reason with him, because he was just trying to get laid. (Yes, seriously. By impressing the female personification of Death via epic sacrifice.)
Preserving that absence of argument, while changing Thanos’s motivation, turns infinity war into a disturbingly cruel argument for culling humanity by implying that movie Thanos had a point (He doesn’t. Over population is a myth.)
The implication the film makes by not having the heroes ever question his motives is that the problem is Thanos’s method, not his premise. Since we know that the good guys will obviously use reason and diplomacy whenever possible. They didn’t even try vs Thanos, no one called him out, even during banter. And this is particularly vile given the fact that his opposition is the entire MCU, thus saying that literally no one in the entire MCU could see a flaw with his logic or goals.
This happening in the same universe as civil war, where argument is core to the plot, is just more evidence of how infinity war is intentionally Malthusian death cult propaganda.
