STEM is an acronym for Science, Technology, Engineering, and Math. We think it's important to help underserved communities have access to these disciplines because they are increasingly important in our modern world, and no one ought to be left out of the conversation due to lack of opportunity. We want to help strengthen technical and science-related programs in schools where they already exist, and to bring new programs to people who have lacked access to them previously.
Great question! One part of the answer lies in the fact that funds which might have been spent on marketing can be donated to a nonprofit instead; the nonprofit's cause is benefited, and in return they help the manufacturer of the product with marketing. Nonprofits have a large reach of committed and enthusiastic supporters, and they can help spread the word about the product even as a cause they care about receives financial support. Everybody wins.