Even the most mild and qualified criticism will do. Adopt a holy, halo-over-head "I feel so bad when I see evil wildlife photographers" pose.
Imply that photography should never have been invented.
Pretend that wildlife watchers without cameras, and indeed, that people who are not interested in wildlife, cannot do as much damage, or more, than the ones who are interested. Don't bother to educate photographers about wildlife ethics, but keep complaining about how they transgress the rules. It feels so good to criticize someone else for something....can any pro wildlife photographer claim that they have never, ever, adopted a less than ethical approach?
SOME wildlife photographers do transgress..but so do a lot of others, why don't we hear anything about them? Because CWP is the Flavour Of The Moment!
The poor guy who's just bought himself a nice DSLR must pay for the sins of someone who went and trampled over a bird's nest. No matter that this guy is quite innocent....they belong to the Same Club, so brand them all.
Assume that all newbies are going to be irresponsible. No One Loves Wildlife Like You Do. You are the Brahmin of Binoculars,and you look down upon the Pariah with his DSLR...
And then, of course, when someone tells you that they've seen x, or y, or z specimen of the animal kingdom, ask, "Do you have a photo?"
Have you made the post yet?