I’m not saying that political movements have to be altruistic in practice. I’m saying the leaders need to at least make a show of working for their followers. People won’t readily follow someone who openly says that empathy for others comes after empathy for themself.

The Russian revolution didn’t happen because the serfs were highly utilitarian and radically altruistic. It happened because they believed that life would improve for themselves and the people they cared about if the communists ruled in place of the Tsar.

Russian revolution was more industrial workers than serfs, but broadly, yes. In other words, they thought the communists would work for their interests. Because they trusted the leaders to work for them, they were ready to make small sacrifices (mostly going on strikes) to support these leaders.

If a movement’s leaders do not gain the people’s trust, their support will not be strong. The communists were preceded by a more radical group called the narodniks, who were mostly middle-class intellectuals, and favoured an agrarian revolution, and later, assasinations of corrupt officials / nobles. Some people sympathised with them, but because they didn’t convince the people that they would work for them (rather than just against the tsar), that ‘sympathy’ didn’t amount to much.