Earlier quoted context omitted.
Stalin was a leader, Marx was a philosopher. > Where Marx saw capitalists (and workers) as forced by circumstance into playing an inevitable role in society - neither inherently good or bad -, Stalin saw capitalists as "wicked men". Because politicians work for a reality change. It's not so obvious to make effective, concrete, viable change in a country, so you have to take shortcuts. Leading a country for change is…
Marx was a politician first, philosopher second. Most of Marx' most influential works were political agitation written as part of his work on organising the first and second Internationals, and actively meddling in the affairs of various socialist parties. He was under regular threat of deportation and arrest for his political work. (edit: and moved countries several times because of these threats) We only see Marx'…
That's like teaching sheeps to unite. It's important to enlighten people, but it won't prevent self interests to collide. Politicians in power can't listen to everyone, it's always easier to listen and talk to powerful minorities who have the strongest self interest.
> Marx was a politician first, philosopher second.
I'd say an activist. I don't see Marx as an active member of a political party, making speeches and announcements. He was more of an intellectual.
When I say politics I say the original etymology of the word politics, meaning having power.