I didn't think Xenoblade was absurdly long. It's a commitment, for sure, but any game so story-oriented (like most JRPGs) will be, and when you throw in all the quests and the kind of potential for exploration that Xenoblade boasts you're going to be looking at a long adventure. The length of its story probably would be off-putting to a lot of gamers, but I think it should be assumed that anyone who actually managed to get their hands on the game is a rather avid fan of the genre and accepting of, or even hoping for, such a long and epic experience. For anyone who did get bored and never finished the game, I'd say the issue was probably that of a conflict between the nature of the game and these people's personal tastes, rather than the sheer length of the story.
I loved how long Xenoblade was, personally. Too often do I buy games and finish them after just a couple of days. With Xenoblade, however, I played the game practically non-stop for more than a month before I conquered the final boss and I enjoyed every second of it. My play time was roughly 106 hours, which excludes most of the post-game content. Since then I've started a new game (with my levels and equipment from the previous playthrough retained) and intend to go through as fast as possible--with no questing or grinding--to see just how long the campaign is at its purest, though I haven't touched this file in months.
As you can probably guess, I'm really hoping that 'X' will be at least as long as Xenoblade. Should Monolith Soft decide cut down on the campaign in an attempt to make the game more accessible, it'd better be made up for with more side content and/or a larger world to explore.