I thought giving Tasha a 'meaningless death' was absolutely the right way to go, gave it a real impact that even a regular character can simply be alive one minute and dead the next.
Yet it wasn't a really recurring theme and many knew that it had been deliberately done to create an "exit" for Denise Crosby (sometimes, ignorance is bliss, I guess).
Imagine they would have killed of Will Riker and left Thomas Riker alive in "Second Chances". But I presume that would have been too bold (I was already excited that they let Thomas Riker live, because I had not expected it).
After the intense discussions I had here at the BBS regarding which of Tasha's four deaths in TNG would qualify as "meaningful" or "meaningless" I'm really not so sure if her death was really that "meaningless".
In a manner of speaking, if it hadn't been her, Armus would have killed another crew member.
In that sense, her death isn't that "meaningless" after all. She "sacrificed" her life on behalf of somebody else, but the decision to do or not to do so wasn't hers.