True, the "role playing" comes before the game in the word RPG, but there's nothing about roleplaying in itself that requires that you have plot outlines. Roleplaying is not synonomous with story-telling. "Roleplaying" in other situations can have no plot at all (like in therapy).
In fact, the purpose of roleplaying in both therapy and RPGs (at least according to one style of gaming) is to *discover* the results of a character who acts a certain way - not to predetermine those results before hand and then play out some farce whose conclusion has already been determined.
And a game typically is defined as something where you make meaningful choices and the outcome is not pre-determined.
Or maybe you might as well be writing a novel rather than playing a game?

My guess is not. But I think that "story vs. game" is one of those "gamer alignment issues". Everybody has a sweet spot for how much railroading they can tolerate in their games. All DnD games have some amount of railroading in them, even if it's just "you all meet in a tavern" at the beginning of the game.
The thing about "climax" is that it's a literature concept, and not really a game concept. There is no "climax" in monopoly or soccer, other than what might arise from random chance. So the more emphasis you put on it, the more towards the story end of the spectrum you are, and the more subjective (less universal) the opinions that follow will be.
I've seen games where people sit around and thespianize all night and never swing a sword or roll a dice or anything. I think to myself "who in the heck would want to spend their time like that?", but it's a foolish question on my part because the answer is obviously "those people". On the other hand, there are (or at least were) people who put a lot of efforts into those tables that you talk about. I don't think the game experience was originally meant to be anything like what you're describing - Gygax has said enough about the early history IMO to contradict what you're saying.
Is there a point to having a "reason to the madness" in a game if you take away my ability to make meaningful choices for my character? What if my character decides to do something that goes against the plot outline? What if the results of my characters decisions makes the events of the campaign seem disjointed and un-story-like? Is the DM then obligated to railroad me back on course because someone on the internet is going to tell him he has a bad campaign? If so, what am I really playing? A game?
It would be misleading for me to suggest that the purpose of DnD is to go around and kill stuff and take it's treasure - but that would be closer to the mark that to suggest that the game is somehow a story-telling process. The roots of RPGs are certainly more about monster-bashing, and I think the jury is out on whether strong plot-lines make for better games. Game and story are two ends of the spectrum and I don't think either one is the right answer for everyone.