Certainly The Munsters was exhausted by the time Munster Go Home (in color!) came out, but I don't believe the same is true for the Batman movie, which I saw at age 9 (the theater gave out photos each "autographed" by Adam West and Burt Ward). The TV series had only been on for half a season (two episodes a week starting in early 1966) and was still very, very popular when the movie came out.
The movie was produced after the 1st season wrapped production. Although season 1 was a hit, "Batmania" was already running its course by the time the movie was released. This was evident with the ratings for season two (1966-67), where the show--despite the pre-season announcement of a number of Hollywood notables to guest as villains--failed to match the eye-opening ratings of season 1.
There was only one, ratings bright spot: the 2-parter with Liberace, which ended up being the highest rated episode of the series, but that was the exception, as the rest of season collapsed.
It didn't start to decline until during its first full season, which led to the decisions to add Batgirl and run only one episode a week (no more cliffhangers) for what turned out to be the final season.
Again, with average ratings taking a serious drop over the course of season 2, Batgirl was added with the start of its
third and final (1967-68) season. It did not matter, as "Batmania" had come and gone a year earlier, and the series had its foot on the gas pedal--running headfirst into a brickwall.
What do you know about "studio expectations" for the movie versus its actual performance? On what assumptions were such expectations based?
Dozier thought (among other things) the film would be a big hit for Greenway/lawn / Fox, based on the reception for the
1st TV season. With a budget of $1,540,000, but barely earning more with
1.7 million in North American grosses, it is not hard to imagine 20th Century Fox was less than happy with the performance. This is notable in that this occurred during a long period when Fox was suffering from incredibly expensive losses on the big screen (not even addressing the TV flops) that would run across the decade (ex.
Cleopatra - budget 44 million / box office 57 million, or 1967's
Doctor Dolittle - budget 17 million / box office 9 million).