The yeti is not the sole purpose of the ride, but it is a shadow of itself without it. The preshow, the queue, the overall theming, and the climactic point of the ride itself is that huge animatronic that used to be absolutely amazing. Now, the theming is meh while the popularity of the ride derives from the "ride" experience of going inside the mountain, outside the mountain, backwards, etc . . . In my opinion, anyone who thinks the ride is still great is living under one of the following delusions:
A. They never rode it in A mode with a working yeti.
B. They forgot how great A mode was.
C. They have a tolerance for mediocrity.
D. They put zero importance into theming. OR
E. They care not for the whole idea of story-telling as part of the theme park experience.
Yeah, it's a jolly good ride as is, but it used to be great. The crime is that Disney allowed a truly inferior B mode to pollute the experience for so long. Indeed, my opinion of Disney as an organization deteriorates a tiny bit for everyday that something other than an appropriate fix is there. An organization that can allow a disco band aid to be the climax of its headline attraction is indeed an organization that has allowed a tolerance of mediocrity to set in. Disco yeti is fine for Six Flags, but it is a diseased symptom of the decline of a once great organization.
By the way, what is the current state of the latest B, C, or D mode?