It's short and scenic, which when one is accustomed to longer linear stories in all major attractions can be perceived as bland, but I argue that from the beginning, its implementation of dimension in media and small practical motor effects is highly impressive. Especially when you consider the time, energy, and design behind all the individual plants and animals, and their subsequent black light painting and the actual disguising of lighting fixtures, and the integration of miscellaneous foliage for the surrounding scenic framing of each centerpiece, and the integration of a water river system with small hills along the banks. And that's just the visual experience. Audio is almost a game changer, given how you can hear the Na'vi singing more and more as the ride progresses and yet only see vignettes of them. Gone are the vocables and yelps of Jungle Cruise's "natives", and in its place is a catchy song with a truly impressive and well articulated singer.
What I'm getting at is that it's sometimes more about your perception of the design that can make all the difference. A first impressions ride is perhaps 20% of how to truly appreciate a theme park attraction, which I'm sure is pretty agreeable. I wholeheartedly agree that more than one animatronic, a longer ride with perhaps a small drop, etc., would've made for a better ride more worthy of a 90 minute wait to guests. But we're not just average guests here, so to call it a waste of space and money is a bit of a slap in the face to the fabricators and artists and designers that were given a budget and told to make the best of it. I think they really did, yknow?