Local Indonesian mythology has it that orangutans actually have the ability to speak, but choose not to, fearing they would be forced to work if were they ever caught. Legends aside, even if this were the case, who could blame them?
There are fewer orangutans around today then you think and there is a very urgent need to address the issue! The consequences of our ignorance and indifference would be very nasty. Here’s a short introduction video on the orangutan situation today: