You can't please all the people all the time. Regardless of what platform you choose there always will be those who as "Why didn't you write it for Blub?" Delivering a top notch application to large market segment has a far greater potential to succeed than a lesser app to a different, possibly smaller, segment.

Your business success will come from how well you support the product and how well you respond to market feedback and implement features that are in demand. You are more likely to accomplish that goal with what you know well and are comfortable with.