Who said kids didn't like it? I was 10 when it came out and every kid loved it. Don't confuse kids with soccer moms. Plus, kids at the time were used to Tim Burton's style. Beetlejuice was a big hit at the time and even had a successful cartoon series. So, kids weren't turned off by the Burton style.
Let's see now - coming off of
the biggest hit of 1989, Batman Returns managed a record opening weekend with a...35% less overall gross and shorter run by
two months compared to its predecessor. It wasn't a complete failure, but it wasn't a complete success either. And Beetlejuice was a tongue-in-cheek
Again, I don't know where you're getting your info from. Don't confuse adults with fanboys. This was the summer's most successful movie. You don't become #1 by people hating your movie. The ONLY people who hated this movie were fanboys and soccer moms. Everyone else enjoyed it.
Then why was WB compelled to completely change the direction of the franchise after BR? Surely soccer moms neither had the political or legal backing to enforce such a change. WB did so because they saw BR for it what it was - a commercial disappointment. No studio wants to see a sequel on which they spent twice as much money only to get 35% less in return. If people thought BR was anywhere as good as B89, then they would've seen it just as many times. But they didn't. Hence the lower box office.
Of course, I hold BR as being
slightly superior to B89, but facts are facts.
Dark Knight, while darker, was also more action-packed. The movie literally began with a bank robbery and then followed that up with Batman in a garage fighting the Scarecrow. Begins, on the other hand, began with a fight scene where nobody could see what was going on.
It still doesn't help your argument that a film needs to have silly moments like BR to attract the kids. And so we revert back to my original point - like TDK, BR didn't need to have those cheesy, silly moments to attract the kids. And there is a clear difference between the box-office of BB and BR. BR smashed opening weekend records, indicative of high interest in the film, yet it topped out at 18 weeks. In stark contrast, BB's opening weekend was the
9th highest opening film of 2005 only indicating little interest in the film, yet it good word of mouth helped it stay for more than 20 weeks in theaters ending with one of the strongest runs of the year. In short, people weren't turned off by the 'boring' content of BB like you say, many simply didn't bother to watch the film in cinemas to begin with.