I love the logic behind Thanos' idea, I just don't like how randomly he went about it - if you're gonna wipe out half the population, might as well go full genocide and kill off criminals, rapists, murderers, homophobes, terrorists, animal/child abusers etc. This is why I liked Light Yagami in the original Death Note, or at least, in the beginning when bad people only were his targets.
To randomly off half the universe is no guarantee that life would automatically be better; he theoretically wiped out a lot of good people - scientists, doctors, heroes, you know people who can help the world be better - along with maybe some trash.
It's like doing the dishes, but only doing it half-assed.