Oops, I wrote an essay. *helpfully points toward the scroll bar*
Tasha was the only character I liked in a series I largely detest. It's a strange dichotomy, for me. I tried watching S1 again recently and I could only get halfway before I quit. You can see right about where the writers just give up and Tasha is relegated to the background, in near silence, falling asleep at the security console, with that occasional break to do the Comm officer's job. It should have been Data opening and closing hailing frequencies. e_e
Then there's "Skin of Evil". In between redshirting the character, using her to directly justify through explanation that "golly, that's what happens to security officers, lolz", complete with the tacked on hailing frequencies gag.... Whether it was intended to or not, it comes across as petty and malicious. And it left the show with only two women, both overtly feminine, Emo!Girl and Doctor Mom. Not my cup of tea. I literally lost interest.
"Yesterday's Enterprise" made up for that with a blaze of glory death... which got retconned into another (allegedly) lame one. What can I say, I fall in the camp of viewers who consider both small children and espionage agents unreliable narrators. Especially since, parents lie to their children all the time, for their own good. I'm still miffed we never got the "real" story follow-up obviously set up by Sela's account, aside from that wretchedly hilarious scene from "Vulcan's Heart". *winces*
And then Sela suffered the same lack of character development as Tasha did, with all the genuinely interesting stuff being pushed to the side in favor of lackluster mustache twirling. I guess her history fell in Gene's category of unacceptably unsavory. If the writers were honestly forbidden from tackling the very background qualities that made Tasha interesting and such a potential foil to most the crew.... I can see why Crosby quit. And then people rag on her acting ability, as if the rest of the cast weren't equally awful with a couple of exceptions. In later seasons, they've gelled as a cast, the camaraderie disguising much of that, but don't anyone tell me that Dorn was a better actor. I might burst an internal organ laughing.
People often say that Tasha's death was necessary for Worf to grow into his, but I believe that's a fallacy. Tasha wasn't stealing scene space from Worf, the bridge tactical officer. His job was to coordinate battle strategy and ship-wide defense in hostile situations. Who actually did that job? Riker, and his job as executive officer was to coordinate department heads and file all the proverbial paperwork, taking over for the Captain as general manager if he were incapacitated. The problem was simply that the characters rarely did their own jobs. Those with three pips or more got the lion's share of screen time (to be expected, I suppose), but they often usurped the supporting cast in the process. Halfway through S1, Tasha, Worf and Geordi become virtually superfluous and, as a result, appear incompetent. The only episode I recall which emphasized who did what job was "The Arsenal of Freedom".
I think that having an actor quit served as a wake up call to the writers to beef up the supporting cast. There are more than enough roles to fill on a large ship - though not all belong on the bridge. So while, I agree that Worf needed something else to do if Riker was always going to play manly tactical officer, killing off Tasha merely facilitated the process. It's with a certain cynical amusement that I note the writers had no trouble at all providing story lines for the CSO once the role was filled by the traditional big strong man.
Because it was the eighties and there was still and over-riding preconception that certain behaviors, like being aggressively protective, were inherently masculine traits. So if a woman did that job it would be impossible to avoid turning her into a de facto man or butch lesbian. Sadly, Buffy and Xena weren't around yet to prove otherwise, and I guess Ellen Ripley only made a small dent. I definitely agree with those who say Tasha was ahead of her time. The writers created a great character who pushed the envelope... but it's painfully obvious when trying to watch S1 that they dropped the ball. Even moreso when I watch "Yesterday's Enterprise" and see that they knew how to do it - we could have had that! - instead of the hobbled, sanitized version of Tasha we actually got. In many ways, I loved both character's potential more than the execution.
Hindsight is 20/20, yeah? Now, if only there were more fic.