Incentives for independent researchers to work on reproducible research
I hope I understand the intent here well enough to offer guidance. I don't think there is any inherent incentive for most researchers to publish more than they do. The current system works well enough for them, so the added effort makes little sense. 

The reason that many US government agencies publish more than the minimum is that much (most?) government funded research here has, traditionally, been considered as owned by the American public. Public Domain, if you like. On an orthogonal dimension, the fact that a lot of science has become politicized, implies that many want to be as transparent as possible so that the inevitable conflicts and charges can be openly refuted. But an additional reason is that "public servant" researchers are also generally interested in others being able to leverage and extend the work they do - for the greater good. They don't work for a profit motive and so have little incentive to hold things close. 

If individuals want to publish code and data, it is, for the most part, permitted, as long as journals don't impose restrictions for reasons of copyright, etc. 

However, a beginning researcher should carefully consider what openness implies. In particular, while you retain copyright (which you can license), you complicate the possibility of obtaining patent on your ideas. It may even be that others, with whose policies you disagree, can use and monetize your ideas against your wishes. Openness in general is good, and being willing to "reveal all" is commendable, but be aware of the implications when you do.