Python fans usually cite the Colt finish and the smooth action. But any gun company can get that finish if they want to take the time to do it. And the S&W action is not generally smoother than that of the Python, but it can be made smoother with a minimum of work, plus it is non-stacking. Getting that Python action takes a lot of time.
Finish is all very well, but let me ask this. If you are the CEO of a gun company, and you can sell all the guns you can make, do you make as many guns as you can with a nice finish to sell at a good price, or do you turn out a third that number with a superlative finish to sell at only a little higher price? I think the question answers itself.