Earlier quoted context omitted.
You don't have to be assertive to be a jerk... ...in fact, I'd say it's the people who correlate assertiveness with jerkiness that are in fact most often jerks.
Would love to hear more about why you think that.
They're ingrained behaviors that people have and most people will usually act appropriately (read: apply those traits) to any given social situation. Luckily most of us are in the middle on this 4-way spectrum.
If someone is acting way out of proportion to the circumstances, you go "that guy/gal is a jerk!".
If you say "assertive people are jerks", or any of those 4 really, you are making a demand that other people accommodate your needs in social situations. It's a social ultimatum, basically, and if you do it, you're a jerk. Always.
You will most often find this quality in passive, turbulent people (this is my natural default) with poor social skills who mistake assertiveness for aggression.
(Tangent: Can we redefine 'passive-aggressive' as 'turbulent-aggressive'?)