I used to bike-commute to the local campus when I taught there. 4.5 miles each way, through a town that is distinctly bicycle un-friendly. I managed to find a relatively flat course through town (we have SF nob-hill type streets around here), but one thing that always amazed me was the way drivers reacted when passing me.
Now, I'm not skinny, and my bike's a 30 year old 12 speed tourer, but I don't really need a whole lane to myself either. I appreciate the 3 - 5 feet that most drivers give me, veering around me a bit as I try to keep to the gutter without falling into the drain grates.
But every once in a while, someone feels the need to give me 10 - 12 feet or more, veering completely into the oncoming lane. And yes, someone got hit once and tried to blame me. It's the same mentality as those who stop at an intersection with no stop sign, motioning the people with a stop sign on, like it was a 4-way stop. There's one of those in front of our house, and the result is an occasional rear-ending. Worse, someone got t-boned when they accepted the other driver's offer, but the car going the opposite way had no intention of stopping without a stop sign.
Excessive politeness can be a hazard... usually only when mixed with stupidity, though.