You are absolutely right about the attitude problem and it came about as a response to the sixties disrespect and relentless pounding by the media.
We know have a downward spiral just like the gender wars inspired by the feminists. The cop hating left has spewed for so long that it's now affects the attitude of general citizens toward cops and cops reflect that attitude right back.
It's a sad ugly mess.
I've sided with the cops on many threads, a lot of them involving a cop shooting a perp and the family is suing, so I don't think I'm a reflexive cop-basher. I get a traffic ticket once every 5 years or so and I don't give them hassle because I know dealing with the public can really suck (and I've always been guilty when they got me, so I figure I'm paying some pennance for stuff I've gotten away with, too). But we're not all bad out here, they need to realize that too. Things have really gotten adversarial.
I don't know where you live, but I have never seen that kind of attitude from a cop and I live in Houston. I have found that as long as I am courteous to them, they are courteous to me, without exception.
Now I am sure there are some jerks out there, but I have never encountered them and the friends that I know that talk about those kinds of encounters all hate cops. Could it be that their attitude is picked up by the cops and reflected in their behavior...I don't know, maybe.