[contingo]

Do you count orangutans as "local Malaysians"? In any case, the rainforest is certainly useful to all of the indigenous humans whose home and way of life are also being destroyed. You might find the rainforest "too dense to walk through" but unique cultures have inhabited them for millennia.

You are, by the way, more likely to contract a mosquito-bourne disease in a town than a rainforest, where much higher mosquito species diversity, plus much lower human population density, equal lower prevalence of the mosquitoes that carry human pathogens.

Also it's not "otherwise it would be all jungle". It's "otherwise more of it would be jungle, or would more resemble an intact jungle in various ways". Intelligent policy on land use and allocation is nuanced, not either/or.

Yes, the jungles are "useful for local Malaysians" in all kinds of ways. But you can find Malaysians from all backgrounds battling for the preservation of their vanishing patches of forests, against the interests of the big agribusiness and timber extraction elites. The forests are treasurehouses of biodiversity and there are powerful aguments to be made on economic, environmental, ethical and custodianship grounds.