Maybe I'm wrong, but I suspect there is more than one way to get up a mountain. You don't have to climb it. It's like combat, I may write a combat scenario up, but the players don't necessarily fight NPCs. It's the same thing with skill challenges, just because I prepare a skill challenge doesn't mean the players approach the problem that way.
What I was replying to was the "you can't bluff your way up a mountain" comment. When I write up a combat encounter, the players might choose to avoid it, and that's ok, but they fight their way through most of the ones I come up with. It's kind of a base expectation that D&D has combats, and if things aren't in the PCs favor to start with then the players try and come up with ways to tilt them in their favor, which largely involves mechanics.
When I design a skill challenge, I have basically two options: I can aim it at their good skills, and they'll probably attempt it (they might avoid it, just like they might an encounter). Alternately, I can not aim it at their good skills, and they aren't going to attempt it because that's "not something their characters would do". The idea of them actually using the SC mechanics to get an advantage on the SC, and therefore win anyway, never comes up because they don't want explicit skill challenges and they don't want to know any of the mechanical stuff (beyond what their bonus on their character sheet is).
So, to me, it's like all of the real mechanical interaction happens during character creation (including leveling up), and not at the table where it might actually matter or be interesting to anyone else (or, well, maybe it's just me). There's RP and non-mechanical stuff, which is great, I just don't need to keep a tally for that. So I don't feel like there is ever any real benefit, to me, in using the SC mechanics. Tracking successes and failures behind the screen isn't fun for me and it doesn't even really work.
Typically I find that SCs hit a point where they have "grind", or even "anti-grind". Either the players have done all of the stuff that they wanted to try with their characters, and haven't gotten enough successes, and either just give up or want to know why their cool plan isn't working - and I can't point to the tally and say "well, you need two more successes..." Or, alternately, they succeed in whatever their goal was (or was supposed to be) by achieving enough successes, but they still want to do more stuff, and they want it to matter.
So it's just easier for me to break complex goals up (when the players come up with them, although I may lay the seeds), say "well, how are you going to go about accomplishing that?", and adjudicate a small, specific success or failure for a skill check. IMO SCs are supposed to feel like that, anyway, right? I know I had some confusion about that when first trying my hand at SCs out of the PHB1, and I wasn't prepared to have the individual checks seem significant in and of themselves, and it kind of sucked.