Mr. Laser Beam wrote:
since Tuvix didn't want to sacrifice his life, he was not worth of life.
Not true. Every Starfleet officer is worthy of life, but they may still be ordered to sacrifice themselves in the course of their duties.
That doesn't make them worthless, it simply means they're doing their duty.
Interesting you used the term "in the course of their duties."
Going to sickbay and dying for two dead individuals is not a part of this person's duty, anymore than it would be ordering Tuvix to turn a phaser on himself, or ordering Belanna do donate her organs to the Videans.