I see people fitting that description all the time in NYC and sometimes in Boston. While I don't adopt that style of riding myself I'm actually pretty impressed at how seamlessly many of them "thread the needle". Is there any real evidence they are involved in accidents or cause accidents at any greater rate than other cyclists?
Many traffic laws are designed for the flow of automotive traffic and have little to do with the flow and momentum of bicycle traffic. Sometimes that kind of rogue cycling may appear "selfish" but may have more to do with survival by instinct as opposed to following convention. I'm not advocating it but just suggesting there may be less of a need for a knee jerk blanket reaction that labels a group of individuals as "Heedless, Entitled-seeming Hipster Cyclists". It seems a little too easy a condemnation to make over an issue that is less black and white and actually has an underlying complexity.