Because OGC already has a suite of standards developed that are highly adopted in software applications, if we make PipelineML compatible with existing OGC standards, we can immediately be compatible with these software applications (ESRI, AutoCAD, Bentley, Integraph, etc.). This includes GML, WFS, WFST, WMS, etc. By adopting and extending these existing standards, we get an enormous amount of capabilities right out of the box.
The Open Geospatial Consortium (OGC) was chosen for the development of PipelineML because their existing standards are well respected and highly adopted throughout many industries (if you use a smartphone, it likely uses OGC standards). Their procedures are well-defined and provide the structure needed to drive the initiative through its maturation. Their strategy is highly practical and not primarily academic – as some standards bodies tend to be. They promote open, interoperability, and vendor-neutrality with their standards as these values have become the bedrock of most data standards across numerous industries.