Fuck you.
But in all seriousness, people bike the way they feel safest. If I am being followed by a large dumptruck that isn’t doing a great job holding its line, I am going to bike fast to get ahead of it: I feel safest ahead of traffic. Sure, they might get annoyed when I’m slow to get off the line at a stop light, or honk when I take the lane before making a left turn, but in my mind, If they know I’m there, they at least have to make the decision to hit me.
And so yes, I was going fast when I swerved around the guy who flung his door open without looking. And I only had to swerve because I was checking my six for the big scary truck when he flung his door out. And I wasn’t really in the door zone, but I was close enough that it was a little scary for the both of us.
The charitable view is that he was scared too, and reacted that way defensively. Most days, I want to take the charitable view. Last night, it was drizzle-misty, I’d worked an 8:30-7 shift, I hadn’t slept particularly well all weekend due to my buddy’s bachelor party shenanigans, and so I was not inclined to the charitable view. So it goes.
The point is, if you’re street parking, look for cyclists before you open or door. If you’re riding a bike, so long as you feel safe and you’re not endangering others, ride however the fuck you want to.