Re: Janeway's Decision to Kill Tuvix
I see it as equivalent to any other Trek episode where a crewman is taken over and controlled by a noncorporeal being. Any captain would have tried to get his crewman back. For Janeway, two of the crew were being controlled by a single entity.
Moe: I'll take the blonde!
Larry: I'll take the brunette!
Curly: I'll take the Black and Tan!
--Wee Wee Monsieur (1938)