I should have made it more clear that I was using "environmentalist" throughout the essay as described as a pejorative term in the first paragraph. This is mostly the view of environmentalism adopted by its opponents, but there is a small minority of the environmental movement that seems entirely dedicated to ensuring that no matter what we are doing, we are supposed to feel bad about it because it's an offense against Nature. This minority is pretty much the lunatic fringe, but they also tend to be the loudest and the ones that get covered by the entertainment programming that America calls the "news" these days.
I don't hold much truck with the folks who would use environmentalist in this pejorative sense, mostly because I think that's unhealthy in the opposite extreme. It seems that those who sling the term as an insult view any position other than "Man dominates Nature, end of story" to be too crunchy granola, which I think is bogus and unhelpful and provably wrong, but in the more limited confines of
Princess Mononoke, uh...they're STILL wrong.
This threw me for a loop when I saw the movie for the first time as well, but over time, I've come to think of it as one of the movie's strengths rather than one of its weaknesses. I also don't necessarily think that you're supposed to really intensely like or dislike anybody in the movie, just as there are no clear good guys or bad guys in it. Everybody has their own short-sighted agenda, everybody has aspects that make them likable (or at least admirable -- I don't think I "like" Lady Eboshi much at all, and I don't think you can really "like" the big spirit of the forest), and they'd all do the exact same things all over again even knowing what they know. Depressingly accurate to a whole lot of human experience, as can be seen in the reactions to any number of current events.
I can't argue a lot with the rest of your comments, since any disputes I have over them really come down to degrees and how much I'm willing to hold them against the movie as a whole. However, I do disagree with this statement. I think the opening scene where Ashitaka has to take down the Boar God is absolutely thrilling and one of my favorite animated action scenes, and I remember the knife fight between San and Lady Eboshi being pretty exciting as well. I didn't think the big climactic battle at the end worked as well as it could, but that was partially because the movie was beginning to topple under its own weight at that point.
Princess Mononoke is one of those movies that I manage to get more out of every time I watch it. I suspect there's going to be a mass Miyazaki fest in the household sometime soon as a result of Miyazaki Week.