Well Said. There are massive crowds at Tirupati, but it does not mean that air travel is the preferred choice of transport for all these persons. I'm not saying they cant afford it, but factors like timings, itinerary, group size etc. affect their decision.
I'm also not saying that this will be the case forever.. When IndiGo enters TIR, it will open up the airport to their nationwide network, drastically increasing the number of possible connections and somewhat reducing ticket price. Traffic at the airport will increase organically.
But lets be realistic. TIR has seen flights right from the 90's. If it hasn't grown in leaps and bounds in the last few years when the industry grew at 20%, then I can't be called foolish for suggesting that TIR does not have sufficient demand yet.