One of our guiding product principles we call "responsible gamification". Everyone knows that creating addictive experiences with gaming elements has developed into a science. It's up to us as product designers to decide WHY to use these powerful tools – to help people better themselves. Stacking bitcoin is like gamifying fitness apps – they help people live up to their own standards and aspirations. As a designer, I would regret creating experiences that were highly engaging but that users felt negatively about how much time they spent with them.