Easterhay said:

Because the pacing of a film when watched in a cinema has to be a bit more ruthless than the pacing of a DVD. Most films seem to get a few extra bits these days in their DVD releases. Look at Lord Of The Rings - blimey, The Return Of The King is monstrously long now. And check out Avatar: two more versions, each longer than the theatrical cut.

Wait, you must have that one disease that makes you defend anything, right? In that case, it isn't your fault and we love you anyway.

The Return of the King isn't monstrously long now... well, it was monstrously long to start with, but not more so now unless you choose the option of purchasing the longer extended edition of the film. The EE was made for extreme fans of the films who want to pay extra to get a bloated experience. The theatricals were still there and the more affordable option too. I really don't know much about the Avatar DVD/BD as I really can't stomach that awful film, but I have noticed there is an extended edition and a standard edition. How can you not see the difference between these instances and TPM were just a few poorly rendered extra scenes have been hacked into it for the one and only DVD release that has ever been made?