Let's say that the engineers and designers at Colt came up with a Python designed on the latest CAD/CAM equipment. The Python would still be more expensive than comparable L-framed S&W's. The edge the Python has, is that the parts are hand-fitted, honed, and assembled by folks who specialized in that type of work. The folks who did that remain only in customer service and/or the Custom Shop, and the ramp-up time to train new folks is just too long to get a new Python to the market.
And the market is not so friendly toward wheel guns. Everything is the "plastic fantastic".
The folks you communicate on this site, the Colt Forum, the S&W forum, etc., are just a small sampling of total firearms owners; and that's not enough for Colt to commit several millions of dollars toward developing a revolver which has a declining market share.
The term is niche markets, and those niche markets are dearly expensive.