Ehhh.

I work at a company that has a similar policy. What ends up happening is:

1) Everyone becomes conflict-averse for fear of looking like an asshole, so bad ideas often go unchecked

2) People find other ways to be assholes when they want to be, they're just passive-aggressive about it instead

3) It becomes a conversation-terminating cliche. Want to stifle someone disagreeing with you? Accuse them of phrasing something in a way that might be considered remotely hostile.

I'm not saying it's a bad policy, but I don't think it necessarily solves much. It trades one set of problems for another.

What you really want is a "no assholes whose behavior interferes with business," which doesn't really roll of the tongue quite as nicely I suppose.