I don't disagree that all people should. But Crocker's Rules are specifically to give the other person permission to give it to you straight because you assume responsibility and maturity to deal with the information itself, regardless of social niceties. And those rules cannot be imposed on the other person: invoking them yourself doesn't mean you can be an asshole back — as the very description of the rules linked in this article explains.
No, abiding by Crocker's rules isn't that you don't take into account other people's feelings. It's that other people don't have to take into account your feelings.
> Note that Crocker's Rules does not mean one is authorized to insult people; it means that other people don't have to worry about whether they are insulting you. Crocker's Rules are a discipline, not a privilege. Furthermore, taking advantage of Crocker's Rules does not imply reciprocity. How could it? Crocker's Rules are something you do for yourself, to maximize information received - not something you grit your teeth over and do as a favor.