Young people in Moscow had no serious reason to protest in prosperous Moscow. In fact, in the context of young people participating in the Yellow Vests protests in France, the protests in Hong Kong, and the protests against Brexit in the UK, it became fashionable in Moscow. The protesters have no other motivation than enjoying concerts and partying during these protests.
When people really want to protest, they do it like the football fans in 2002 – with violence. Or like in the 1991. And, for example, the Soviet people protested in silence.