The problem with malaria...

In short, evolving genetic resistance to malaria seems like a better route than trying to prevent or treat it. I’d like to understand why that’s controversial (I’m assuming it is). EA-ists are surely (some form of) utilitarians. Isn’t it more likely that trying to combat malaria will produce more suffering (by keeping non-resistant strains in the gene-pool) than by allowing us to evolve resistance?

I’m not saying ‘stop trying to treat malaria’ exactly, but I am saying ‘maybe we should put our long-termist hats on and reconsider whether it is actually (so clearly) a good thing to do’.

I’m almost certain I’m overlooking something, so looking to correct my thinking (i.e. please don’t attack me, and rather help me understand).