Greg Cox wrote:
To add a bit of historical context, however, nobody back in 1966 worried about shows being too "Monster of the Week." That wasn't even a term back them. Nobody expected ongoing story arcs or character development on network shows, let alone sci-fi adventure shows. Heck, "The Outer Limits" was literally a Monster-of-the-Week show and "The Twilight Zone" was an anthology series.
Well Greg, the term was not there when TOS was first run (it popped up in the 1970s), but from friends who watched Lost in Space
on CBS ('65-'68), they said the series made them expect
a monster every week. Same with most seasons of Voyage to the Bottom of the Sea
Perhaps, but I think "Monster of the Week" being a term of derision, as in "I prefer ongoing arc plots to mere 'Monster of the Week' episodes," is of far more recent vintage, dating back, probably, to Buffy
or The X-Files.
Nobody in 1966 would watch "Mantrap" and fret that Trek was going to be too "Monster of the Week" because that wasn't something anybody worried about back then. Indeed, as you said, people rather expected sci-fi shows to feature a different monster every week. That was just par for the course. The Salt Vampire would not have been cause for concern.