Why are there no vadewale's in South India?

Just curious, we have idli dosa walas at almost every 100m in Pune. But in Hyderabad and Bangalore I've observed those people very much prefer their local dishes over anything else and even there those are overpriced and at our side idli dosa are comparatively lower price. And also vada pav is rare and extremely overpriced there with third class taste and quality. Idli dosa are commonly available in Pune but vada pav is rare in other South cities, why?