The point of a team is that no one person is a point of failure.
Exactly. Tuvix is a potential single point of failure. You’re doubling your risk. Eggs and baskets.
Factoring in a hypothetical future scenario is spurious.
Why? It goes hand in hand with your point about points of failure. It’s something that would have had to be considered. Voyager wasn’t snug and safe in the alpha quadrant where they could just go to a starbase and get more crew members if they lost any.
And not one person has even tried to reconcile the speech to the Vidiians.
It’s right there in the speech I will do whatever is necessary to protect my people
At the end of the day the murder of Tuvix pales into insignificance compared to her out and out genocide of the Borg. All to protect her people and get them home.
I don’t personally think the murder of Tuvix was justifiable, but it’s definitely not an open and shut case. Janeway had to consider 150 people and their chances of surviving and getting home in one piece she also had to consider Tuvok and Neelix.