It is cheaper to NOT put the lock on and bring back some customers than keep the lock on the gun. So it is NOT a purely economic decision
Pity the poor Old Fuff, 'cuz he's so often misunderstood.
A lot of changes in S&W revolvers were based on economics, because to keep a price point that customers would accept they had to reduce they're production costs. MIM lockwork is an example.
But the lock was not one of them.
However, if the Ruger becomes an outstanding success, both Smith & Wesson and Taurus will loose market share, and and thereby sales.
Bottom line: Sales are the name of the game.
So if Smith & Wesson as well as Taurus see a decline in sales they will likely respond by looking at their current products and what can be done to make them more attractive in the marketplace. At that point the lock
may become part of a larger economic issue.
So far as locks are concerned, Taurus doesn't have a problem. S&W might go several ways regarding the lock: (1) Do nothing. (2) Remove it. (3) Redesign it in a way they hope would satisfy everyone. (4) Start an advertising campaign to "sell the lock" to the buying public.
What will they do? Only time will tell. It should be noted that Smith & Wesson, Ruger and Taurus all have internal locks in at least some of their models. It would seem that only Smith & Wesson is loosing sales. If that number increases enough they will notice.