Killing off characters like anything has pros and cons. SG:A killed off at least two of it's leads Beckett and Weir, was it a good move that's open to debate. But in the case of Beckett the fallout was so bad they had to bring the character back (via a clone).
I actually like Stargate Atlantis but I never saw the point in killing off those two characters.
Well thats my point they should have allowed the contracts so that they could kill off the main cast and in a meaning full way.
Take year of Hell. Maybe Chakotay could have died takeing out the time ship ? Im sure the actor would have loved to have parted ways from what I heard.
In Unimatrix Zero someone could have been left to the borg ect
Beltran wasn't that frustrated at that time "Year Of Hell" was filmed. That came later when his character had been even more pushed in the shadows.
But maybe they could have killed off all the main characters in season 2 or 3, replacing them with uninteresting no-no's, just like in the recent books. Then we could have been spared from the dilemma of having favorite characters in a favorite series. Then we could have done more meanigful things in life, like watching wet paint dry or get bored to death by watching BSG or Stargate Universe.