... so should we only ticket drunk drivers if they have committed a traffic error too?

Your argument implies that people should be able to engage in risky driving as long as they are still in control. Speeding, driving on the wrong side of the road, drinking and driving, and texting and driving are all against the law because they are reckless behaviors likely to cause accidents. The idea is to prevent the reckless driving in the first place, not ticket it only when it has already happened.

Your analogy of the robbery arrest is flawed. People are receiving a ticket for breaking a law, not for appearing to be likely to break a law. Additionally, being dressed like that doesn't actually make you more likely to rob someone. The illegal behaviors listed above are indeed indicators that you are more likely to cause an accident than someone not engaging in them.

You're only in control in those situations until you're not. I have a feeling that many people who cause texting and driving accidents think they have it under control... or they wouldn't be doing it. That's part of the problem.

I wish I wasn't ALMOST ALWAYS the 2nd vehicle at the stoplight. I really don't like having to be the alarm clock for the 1st car in line that doesn't move when it turns green. And for the record, I give you people at least 3 secs before I honk and holler GOOOOO GOOOOO GOOOOO like you can hear me.