The technology infrastructure just doesn't exist. From major subsytems like Engines, Radar, CNC Texture weavers, FLIR, to smaller systems like actuators, load cells, US transducers, Opto-electronics, metallurgy, ... It will take years to develop the technological environment to support multiple tech projects efficiently in India. ToT is a rather recent (last 3 decades) phenomenon and will set up the indigenous industry to take up technological challenges, the PIII implementation of AL alloy stampings, Air fame structure, in house designed servos and Actuators, and mission electronics for MKi is a prime example.
IAF cannot wait for another 15 years to get decent jets, and Rafale was evalauted as the best option for the IAF... Making strides in aeronautics is uphill task for any developing country, In another 10-20 years, we will see better results, just like we are seeing the achivements of ISRO today, due to the investments made throught the last two decades in the organisation.