The problem is the thing that tulpas contribute is something 99% of people have in overabundance, and those that don't have it don't because it can't be transported to them efficiently not due to sacricity. Tulpas are duplicate of the software almost all human minds already run, and that software was already utilizing all the resources as effectively as it can any. Their only real use (companionship) is already a hack, and other than that they are a technical curiosity, sort of like quining computer programs.