This paper is a reflection by the authors on our more than twenty years of work to realize an in-vitro blood gas system based on fiber optic chemical sensors. We offer reflection based on our experiences in these projects. It is not our intention to present data for critical review but rather to ask the critical questions of the technology and its application. These are the critical questions that should be asked of every new technology up front, before numerous development projects, man years of effort and a fraction of a billion dollars are expended. These are the critical questions which would have detected the on set of the "hobby horse" syndrome. The developers of this technology fell in love with the technology. It was this love and our passions which ran un-checked and have yet only delivered one commercially successful product.