Don't have a problem with the secrecy. A rather large number of big budget blockbusters have had much tighter security and secrecy.
Lucas used to give certain actors only the pages of the scripts (for ESB, ROTJ, and the prequels) that they were actually in, so that not even they knew what the overall story of the film they were shooting, and therefore couldn't let it slip in front of members of the press. Heck, David Prowse was such a notorious blabbermouth, and would later be overdubbed by James Earl Jones anyway, that George opted to give Prowse script pages with lines to speak that bore little resemblance to what would later be dubbed over him. Prowse didn't find out that Vader was Luke's father until "Empire" had it's premiere. Up til then, he'd been under the impression that the secret he shared with Like about his father's fate was that Obiwan had killed Anikin for allying with Vader.
And Lucas isn't the only one who limits actor's access to full scripts.
One of Seth Green's first big screen acting roles was in a Woody Allen film, and he claims that he didn't even realize that he was playing the younger version of Woody's character until after
he wrapped shooting on the film.
And I believe it was Paul Reiser who didn't realize that his character of Burke was the bad guy in "Aliens", until his very last day of shooting, when Cameron gave him "new script pages". From what I hear, in the script that Reiser was originally given, his character was cut off from the group, and assumed dead until he unexpectedly resurfaced at the 11th hour, only to become the accidental hero of the piece.
Cameron also apparently pulled a lot of script-misdirection on the actors in "The Abyss", not only to keep the full tale away from the press, but to surprise his actors into reacting to scenes with genuine spontaneity.
The thing is, such secrecy has been pretty commonplace for 30-odd years now, and the trend is growing by leaps and bounds. So if it's something you're tired of... I guess it really sucks to be you.