Yes, it is frustrating when you see rules on a site not "enforced." However, you quoted from the TOS that covers the entire website, not just the community. The Terms of Service are necessarily broader and more direct because of the need there to have effective means of shutting down spammers and others on the site.

You should focus more on the Community Guidelines for the community, since that is what we use as the guiding set of principles here.

Basically, we're not here to be referees to every argument that breaks out between two members. We get tons of people asking us to intervene in such arguments, but frankly it is beyond our means to do so. And frankly, I wouldn't want to do so. We're not here to play that role. We expect most adults to act like adults and find a way to deal with their issues with others, or use the technological functionality we have in place (e.g., ignore).

DocJohn