This fool saw that HIS world was suffering due to limited sources and wanted to stop that. Alright. I see his points, I understand his frustration. Almost no one is taking overpopulation seriously. He watched his entire world fall apart. That can mess you up. There are planets suffering from overpopulation, like Earth, and it's going through the same thing his planet did. Okay, cool. Motivation makes sense. It's driven emotionally and logically, he has personal stakes in it as well, and...
And this is absolute moron decides the way to prevent more suffering is to create an endless amount of it until everyone drops dead?
He has not visited every single planet in the universe, he has no idea which ones are actually suffering from overpopulation except those he's seen, and his solution is to wipe out 50% of every species in existence? Any species that has less than 50 would get around 25 and suffer from inbreeding. 50% of the insect population on Earth would vanish, too, and since insect populations have been decreasing (although it's hard to calculate by how much), this would have devastating effects on the planet. He even took away trees. Dude, all life also means all life on the molecular level. The healthy bacteria in us? Also alive. Until the Snap. In which case it is all dead. Half of our blood cells? DEAD.
I'm not going to get into how the MCU failed on all levels to show how catastrophic the Snap would have been, and how the characters would not have been living the lives they were years after the Snap, but the vast majority of life would be starving slowly to death if it's even alive anymore. Those who wouldn't be are completely and entirely messed up on the molecular level so it doesn't matter! All of us are dying. No suffering has been prevented. This dimwit just caused more suffering across the entire universe than there may have ever been all at the same time.
And he could also make things appear into existence anyway and bend matter and reality and--- JUST BEND REALITY INTO PERFECTION AND MAKE INFINITE FOOD? Better yet, change reality so that nothing ever has to eat again! Ta-dah!
Thanos has the most flawed, and stupid motivation I have ever ever seen for a character. I've read his comic version's motivation is to impress "Death", who looks like some hot lady. That still doesn't make sense when you think about it, but it at least makes more sense than MCU's Thanos because MCU's Thanos wants to prevent suffering and he's not doing that on any level whatsoever.
Some have said, "Well, he's a psychopath, that's the point!" but psychopaths don't have to be idiots? What was his plan when, in the unrealistic-setting of the MCU where a lot of people are still alive after the Snap, populations returned to how they were pre-Snap? He messed up his hand, is he just going to use his other hand? Okay, that's a plan, but what about the third time? He clearly has the ability to think about the future because he did it with his planet. But nope. No foresight. No real planning.
Thanos is the worst.