Could have been an interesting way to go with the series though, new doctor at the beginning of each season. Look at how many Chief Engineers Picard went through.
Although Chief Engineer Argyle (who appearrs twice and is mentioned but not seen in a third episode) was allegedly a contender for becoming a regular on the show. Wil Wheaton recounts
Wil Wheaton wrote:
The Chief Engineer of the Week in this episode was Argyle, played by Biff Yeager. I don't know if it's entirely true (and this is recalled over twenty years, through the memory of a 14 year-old) but I remember hearing that Biff was under consideration to become a permanent Chief Engineer, until the producers found out that he (or someone acting on his behalf) had encouraged Trekkies to write letters asking to have him on the ship full time. There's nothing wrong with a letter-writing campaign, but it helps if the letters come in after your episode has aired. Yeah, apparently the letters came in before this show went out, and some Trekkies complained that they were spammed via mail (this was well before e-mail was widely used) and those two factors sent Chief Engineer Argyle -- and Biff -- to the Cornfield.
It was pretty obvious early on that having a big engineering set and no characters obviously tied to engineering was a mistake for the series, which is why you got stuff like Geordi, Data and Riker going down there to science the science, an episode where Riker claims that oversight of engineering is a first officer perogative ("Where No One Has Gone Before") and, of course, a procession of engineering guest stars.
Putting Geordi down there was really one of the best calls to make.
I always got the impression that "Ethics" was handcrafted for that specific purpose, but it just never worked out that she would come back.
I don't think there's any evidence that the episode was ever written with Pulaski in mind but it would have been really sweet if she had
appeared. While Tasha got mentioned fairly often after season one (we met her sister, Data mentions her in "The Measure of A Man", etc.) I think "Who Watches the Watchers?" is the last time Pulaski is ever referred to.
I like Pulaski. But I also like Crusher, although I don't think the series really got a good handle on her until her return in the third season.