I'd gesture back, but you might run me down

I finally managed to retrieve my stranded bike today due to the fortuitous overlapping of a day off and a day with decent sunny weather. But on my way home, as I was crossing a busy six-cornered intersection (where three streets pass through one point and it's generally a little nerve-wracking to ride a bike through), I heard honking and turned to see a white middle-aged man in a pickup truck gesturing angrily at me.
Of course, that kind of ruined the ride for me. I spent the rest of the trip home wondering what I could possibly have done to this man to make him react like that (I was riding over on the side, as much out of traffic as I could be, and making my way across the intersection with all due haste when the event occurred). Does he just have a grudge against bikers in general, and I happened to not fit in with his idea of what should be happening at that particular intersection? Chicago's drivers and bikers have what I presume is a typically contentious big-city relationship; there are just too many people trying to get too many places and not watching as well as they could be. When the city recently passed laws designed to protect bikers, mostly consisting of fines and other legal reprimands for things like dooring people or not leaving enough space between a moving car and a moving bicycle, there was an outpouring of comments from drivers asking whether bikers would start being similarly punished for blatantly breaking traffic laws and even endangering drivers through reckless behavior.
Even though I've mostly been a biker in this city, I can definitely see the point. (Or part of the point: I still think it's stupid and annoying to give bikers tickets for running stoplights in the middle of the night or not coming to a complete stop just before a hill, but I also think that we should probably try to follow at least the common-sense types of laws. I just tend to treat them more as guidelines.) Traffic here is bad, and I've definitely seen lots of bikers do things on the road that caused more inconvenience for others than I could personally take responsibility for if I were to consider behaving the same way. But at the same time, I ride in constant fear of being doored, hit, run off the road, and yelled at just for my presence. I guess all I'm saying is, I won't cut you off in traffic and slow you down too much if you don't knock me off my bike or gesture rudely when all I'm trying to do is cross the street and behave like the car that the law pretends that I am.