Disagree all you like, but I recall the coverage and promotion of the film first hand (I was 26 in 1989, and yeah, most people I know were more interested in seeing Nicholson's take on the Joker than Keaton's take on Batman. Most people were remembering Nicholson's performances in "The Shining" and "The Witches of Eastwick" in leading up to this role as The Joker.
Well, there was a fain amount of attention--in the form of controversy about Keaton's casting as Wayne/Batman, since he was a balding, nonathletic comedic actor who looked nothing like the comic character who had trained himself as close to perfection as possible in order to wage his war on crime.
That said, the on-again, off-again Batman movie scripting, announcements, etc., throughout the early to mid 1980s had a number of trade publications theorizing about who might portray The Joker if he turned out to be the villain, with actors such as a young Willem Dafoe's name mentioned (based in part on his performance in 1984's
Streets of Fire), along with Nicholson.
As for the batman 1966 fans, they were upset Adam West wasn't even considered (when the film started production Batman the series was off the air for only 18 years, and the Star trek TV cast showed it was possible); and that he didn't even get any sort of cameo.
The essential difference between TOS' cast returning is that their actors & the characters they developed were taken seriously; they were not some quasi adventure/parody like the West/Ward series, and in the 21 years between
Batman's cancellation (actually, even while it was first run on ABC) and the premiere of the Burton film, the general consensus among comic fans was that the '66-'68 TV series (and West)
disrespected the character (I've posted some 60s
Batman / Detective Comics reader letters making such complaints some time ago) while regular audiences wrote it off as silly. TOS--in only a couple of years after its cancellation was considered and respected as a cultural milestone (and one of the best examples of filmed sci-fi) so when the rumors of Trek returning as
Phase Two, then the movie were white hot, not only was there a natural expectation that the TOS actors would return, but they--unlike West--were not considered "wrong" or something to be laughed off.
Regarding West not getting a cameo, again, he was not taken seriously and in theory, could have been considered a possible distraction. That's the opposite of the effect I recall from Kirk Alyn's cameo in Donner's
Superman, since Alyn was thought to have been a great Superman in his serials, so his appearance was very, very welcome.