I think you have missed the biggest point about the TATAs. They have never been traditionally aggressive and pushy in their sales strategy for any of their products or services so far.
Also, I think you missed weighing the global inflation trends in your argument which has had a huge bearing on the cost of material which never helped TATA's strategy of having a reverse priced product for a price sensitive market like ours. A reversed priced product is where the price of the product is decided first, the quality of the materials used and technology in general are worked backwards to provide a quality which is better or at least equivalent in the existing market.
A reversed priced product is generally good in markets which do not experience very high rate of inflation. However today, the high rate of inflation is a global reality across all regions.
Therefore, it looks as if TATA NANO "reneged on the promise" of making a car worth a Lac since the price of the car now is almost double the initial launch price. It is priced at around Rs.2.20lacs which is almost the price of a maruti 800 back then, therefore beating the whole idea of NANO being a cheap car.
Besides, I think you must check the source of your mileage facts. Tata Nano gives around 23KMPL better amongst its peers such as ALTO, SPARK, etc.