It's certainly exploitative but from Woody's viewpoint it sounds like he might have managed to arrange his life exactly the way he wants it. He gets to have all his favorite stims (at least, three of them, no requirement to choose) continuously and uninterrupted for apparently as long as he wants, as long as he waggles his fingers in the designated general direction. For this arrangement to have come about, he must have expressed displeasure with different simpler arrangements somehow, perhaps by withholding the finger movements or perhaps by other more conventional nonverbal means. It's likely he also signals what he finds acceptable with regard to food, toileting, and the like by more conventional nonverbal means as well.
I accept that he would be better off (in terms of having his wants and needs better satisfied in the long term) if he were taught to communicate more genuinely with techniques that actually work. However, such learning is also stressful, with a lot of frustration on both sides of the process. Such as, measures to focus his attention on repeated attempts to communicate with him that he doesn't yet understand, as well as frustration with his own attempts to communicate back that are not understood. (For an ordinary child at school, these correspond respectively to having sit quietly in a classroom instead of playing, and turning in work that's marked wrong.) The rewards are worth it, but like a teenager who would rather play video games than play sports or study, I can understand why he might prefer things the way they are right now.