"It is almost impossible to speak of ethics without using words like should and shouldn’t, right and wrong, good and bad. There is another way to think, though, and another way to live. In trying hard to be good and rise above desire, we enact a war against the self—an internalization of our civilization’s war on nature."

And so I assume its better to just go with our desire everytime, and trust that it will have each of us do the "natural"/"right" thing? Apparently, as you say:  

"Interestingly, desire and pleasure lead me to the same behaviors that people consider ethical. I recycle and compost because it feels good, not because I should. I am kind and gentle in my relationships because it feels good.. To take an apple core and throw it in the garbage instead of composting it actually hurts. Because I am connected to it, and I know where it wants to go. Its pain is my pain. This is not a theory, it is a felt experience that everyone has access to."

But our desires are different.  Ethics purports to provide a general structure and set of rules that we as a group of people will live by.  Jeffrey Dahmer had the desire to cannibalize young men  and engage in necrophilia.  Not a very ethical thing to do, because his acts had huge repercussions on others - the victims and their families suffered terribly. 

Its basically the Hobbesian tenet - we balance our own freedoms to follow our desires with a desire to be somewhat protected from the impact of the desires of others on us.  Ethics is about deciding where that line gets drawn. And deciding who gets eaten and who doesn't is an appropriate place for an ethical inquiry.