Here's one of the reasons:
The most worrying part is that in Russia that is considered a funny minor incident.
As it turned out later, the bloke on Lexus, who initiated the assault (and was rightfully beaten thereafter), was a participant of the ruling party United Russia's primaries. Moreover, the state TV channel Russia 1 has released a program that tried to justify his moronic appearance.
That's basically all you need to know about United Russia and Russian television.