I never judge vanity or motivation for vanity plates. I enjoy them & enjoy figuring out the difficult ones & chuckle at the funny ones.
I'm a bumper sticker kind of person. I don't know why I want the whole world to know my preferences, causes, and anything else I put on my bumper. I've heard that bumper sticker drivers are more aggressive - some study or other. That may be so, but I try to be a considerate driver & I try to practice patience & tolerance, too. 6 years ago, I was very ill & under treatment, but still driving daily from Pine to DTC for work. Due to the medication, I could only (fearfully) drive 285 at 40 miles/hour. This was quite a change from my usual 64 miles/hour. I was honked at and flipped off many, many times, but I was driving the best and fastest I could at the time. So, when someone ahead (in the right lane) is going along slowly, I think that they might be going as fast as they can for whatever reason. I don't get angry or rude since I've been there before myself.
Anyway - back on topic - I just tool along and enjoy all the vanity plates on the road