If somebody manufactured a nearly rust proof, hand coned, dyno tested pipe... Now that's a new market.  Let's also say it was manufactured in limited numbers...  Imagine the demand for something like that. You'd be the new kid on the pipe block for LT's. 

Hand coned steel pipe are very time consuming to build.  Building a hand coned, all welds hammered, stainless pipe will be much more time intensive than a steel pipe.  This would make the cost out of reach for the majority. 

Another concern I have is reliability.  Even when the manufactures use back purging and all of the tricks necessary for proper stainless fabrication, I repair a lot of stainless steel and titanium 4 strokes pipes.