What are films made for? Do they cater to peoples tastes or are they 'safe bets' for the Hollywood Industry?

In my opinion, Hollywood films have become safe bets for the industry for many reasons. One reason is that most films now are sequals, book adaptations, or remakes of older films. For example, Tim Burton has recently remade the famous Disney film, Alice in Wonderland, putting his own unique interpretations in to it. Alice is one of the most popular Disney films, therefore a remake must be a safe bet as people will be interested to watch a modern version of it after seeing the original. Also, Cormac McCarthy's post-apocalyptic prose (which won the Pulitzer prize in 2007), The Road, has been adapted into a movie. It was a popular book, so Hollywood producers thought it would again be a safe bet to make it into a film to see how they would adapt it from a book into a film.
Even TV shows are being made into films, like The Simpsons and Sex and the City for example. The Simpsons is a huge television show which appeals to a wide audience. Film makers would have thought this to be a safe bet for the industry as it has been popular to audiences for 21 years. A film adaptation would rake the money in for sure. Another example of this is the Hannah Montana Movie. It is a very popular childrens TV show on the Disney channel, and lots of little girls aspire to be like her. Therefore, the film version would be a hit.
The relationships between the actors and directors are often very important, and are another reason why films are mostly safe bets for the industry. For example, Tim Burton has Johnny Depp playing the lead role in almost every one of his films. This is because he knows that Depp has a huge fanbase, and with both of their fanbases put together they will have a massive audience and will make lots of money. Depp is a sefe bet for him because he is guaranteed to make a profit if he puts him in a lead role; this is what sells his films, and the fact that Depp is doing interviews with Burton on the new Alice in Wonderland proves this.
Another reason why they are safe bets is that the release dates of some films like Saw:
Saw 1 - 1st October 2004
Saw 2 - 28th October 2005
Saw 3 - 27th October 2006
Saw 4 - 26th October 2007
Saw 5 - 24th October 2008
Saw 6 - 23rd October 2009
As you can see, they are all very close to Hallowe'en. They are very gory films so they keep with the theme of Hallowe'en, therefore the producers/directors of Saw would be guaranteed to make a profit from the films. Also, because the first one was so successful, more and more were made being released one after the other. If audiences liked the first one, then they are likely to want to see the next one and the one after that.