I am a firm believer that saying what you are not can be more informative than saying what you are. So yes, the option to "negate" values is on the roadmap :)

Re: ambiguous "value tags", they're up for interpretation. I encourage you (and others) to read how different teams describe the same value and what it means to them. Also, there are several teams who didn't choose Creative + Innovative, Customer Comes First, and/or High Quality Codebase.

No company will "advertise" that they do not produce high quality, but we still learn something when high quality code isn't included in a team's top values. This is the beauty of limiting teams to 8 values :)