Your mentality is false from a marketing point of view...
Manufacturers just want to promote a model not a specific version. No matter how many sales the ST has it will never be a high profitable car for the company.
Look at citroen for example all these years in the WRC with all those titles and they have not produced a single high performace vehicle based on their WRC worth mentioning... even the c4 Loeb version was a trash.
Only Mitsubishi and Subaru promoted their road going versions through the WRC and we can see how this panned out for them...