He had some funny films at the start of his film career but my main problem with him (besides the voices and fart-jokes) is the fact that he seems to make a movie about every stupid idea he gets in his head. I think he can be funny but he should slow down and take the time to write and re-write scripts until they are actually good and make one movie every 3yrs instead of what seems like 3 movies per year!
He owns his own production company "Happy Madison Productions" so I would assume he pays for and produces his own films that are picked up and distributed by larger studios. So he doesn't need "pull" to make movies, like I said he can make any insane idea that comes to him. I am not exactly sure how the money flows in the film industry but my gf forced me to watch "Jack and Jill"(horrible 1/10, the 1 given only for Pacino) and this movie was produced by HMP and distributed by Columbia Pictures, with a budget of $79million and it grossed $148million, so if Sandler's paying to make his own films then we are going to see this crap for a long time.
Speaking earlier of blaming Sandler for Rob Schneider, ironically it looks like it was Schneider that got HMP rolling in the first place. Happy Madison Productions made "Deuce Bigalow" and "The Animal" with Schneider's first two movies grossing $130million more than the budgets, while Sandler's first HMP film "Little Nicky" lost around $40 million.
It is interesting to note that looking at HMP's budgets for films, any movie with Sandler in it has a budget of >$75m while any movie starring an SNL buddy has a budget of $16-$25million. Sadly though, if you look at this list, the majority of his films make money so there will be more crap to come.
http://en.wikipedia.org/wiki/Happy_Madison_Productions#Filmography