That'd be all good if the creators of the movie didn't
confirm he literally killed half of ALL life, plants and animals included, which means the issue of too many mouths to feed with not enough resources was not solved. The power of the Infinity Gauntlet grant's him countless alternatives to solve the issue that don't involve erasing innocent lives. Dying a natural death is better than someone you don't know exists arbitrarily wiping you or your loved ones out of existence. The people who didn't get dusted have to deal with the aftermath of this man's actions while he sits on a farm patting himself on the back. The "good" intentions/motivations behind a heinous act don't make said act less heinous. When Thanos snapped his fingers, was his own chances of being erased also 50/50? Lastly, the dude had been committing genocide on a planetary level long before he was able to simply snap his fingers. He pushed his daughter off a cliff
He promised to spare the people of Tyrion's world if he made him the gantlet and then killed them anyway and took Tyrion's hands
Evil is an understatement when it comes to Thanos.