The reality is there may be no real mechanical flaw that leads to an uncommanded discharge. So far, no one has been able to produce evidence of anything specific.
However, if they had addressed the drop safety and added a trigger safety from the get-go, chances are even if there IS something, it would be so rare it would fade into the background.
But now the P320 is going to be remembered forever as "that gun that goes off on its own" and it'll be hard to even give them away. And Sig's response to this whole debacle has been terrible. Making the drop safety fix a 'voluntary upgrade' instead of a recall, and now crap like this just makes everyone view Sig in a bad light.
Reputation can be everything for some industries - and for safety especially. (See: Boeing)
Guns, and pistols in particular is a wiiiiiide market with a lot of players. If one reputation goes down the toilet, people will just buy from someone else. They have 0 reason to stick with Sig in particular.
IMO these companies do the bog standard math of (chance of accident * legal cost) vs (cost to recall and repair guns). They don't consider a critical aspect - reputation. Once lost it is very hard to regain and hurts future sales of ALL products, not just this one.