Nope.
I don't buy it. That's poor game design. Neither Halo nor Halo 2 have a lot of plot. There is certainly room for more in Halo 2, and in Halo 3.
Everyone keeps saying the story HAD to be cut in half. Bull shit. You can tell one full story in Halo 2, and one full story in Halo 3. If that story ends the franchise, then either tell another story, or move on to another franchise. Don't short change your product simply to make more money.
Good level design is good level design. The plot doesn't dicate that you can only have X number of levels. If the battles are good, they're good. Metroid Prime 2 has no real plot to speak of, but they have plenty of FUN levels.
The game could have been longer. It could have had more story. But the fact is this is the game that Bungie wanted to put out. They designed it this way, and this is what you paid $50 for.
I think certain people are so die-hard in their Bungie worship that they can't approach, let alone grasp the concept that they may have been short-changed.
Then again, if you're content to pay $50 for Halo on Live, then go ahead. If you're happy, I won't argue. That's your right as a consumer to decide where to spend your money. Hell, they sell a $10,000 martini in New York. If you think it's worth 10 grand, then buy it.
My opinion is that Halo is overrated, and Halo 2 is certainly not the second coming of Christ.
For many people it seems that Halo was their first LAN game. They discovered good multiplayer gaming, and associated that fun with Halo, and not specifically with LAN gaming in general. I'll take Counter Strike Source over Halo 2 any day of the week.
I urge people to open up and try other good LAN games.