The character wasn't that popular to warrant inclusion in a film.
Right. Because the previously unknown Romulan clone of Picard with a dubious and implausible backstory was so much more popular.
C.E. Evans wrote:
Sela wasn't Picard's nemesis
Technically, she was. Picard, after all, was the one who sent her mother to certain death at Narendra-III and who thwarted her efforts in the Klingon Civil War and the invasion of Vulcan. Shinzon's motivation actually fits better with Sela than it does for Shinzon: the Federation really DID abandon her and her mother, and Picard really screwed her over on two separate occasions.
And then there's Picard agonizing over Shinzon's unfortunate childhood and feeling all responsible for him. That sentiment earns a yawn if it's a clone he never knew about until now, but it would be a bit more powerful if the anguished Romulan adversary is actually the daughter of one of his former crewmembers, a woman whose existence he is actually responsible for (even if he doesn't remember it). If you consider the final scene on the Scimitar's bridge with Sela staring down Picard impaled on a pipe: for him, it would be like watching Tasha die all over again.
LOKAI of CHERON wrote:
With all due, and genuine, respect to Denise Crosby, I don't think she's quite strong enough an actress to have pulled off a major guest starring role in a relatively high profile movie convincingly - particularly with the Sela character. Honestly, I think TPTB would have considered that had her name been even half seriously bandied about.
And yet, consider the alternative:
I'm not saying Sela would have been an awesome villain for Nemesis. I'm saying that the bar for this movie is already set so low that Sela could not possibly have been worse than Shinzon.