Because of lack of commercial value to that sugarcane variety in the Commercial profit making Agriculture. That black sugarcane was suited to Subsistence Farming. Now a days farmers grow varieties with high brix value and which fetches high price by sugar industry
Everything depends upon demand. If there is no market for the produce, the farmers will not grow it. At the same time, there will be no breeding work on this type of crop to develop high yield varieties by the scientists.
Most of the commercial varieties are crosses with S Officinarum and wild relatives like S. Spontanium or Erianthus. The best agronomic quality has been achieved for commercial benefits than pure officinarum. eg. disease resistance, high photosynthesis, biotic and abiotic stress tolerance. Badilla was a commercial variety in very early stage of sugarcane industry. But now the economic genetic value is very low in comparison with most of the commercial hybrids.