@mamalion Activism without service is just cheap talk. Sadly many people talk a great game but are too elite or busy to actually get their hands dirty.
Feeding the poor, tutoring, providing free legal and financial advice, visiting the sick, visiting the lonely, hiring disabled adults are all ways to, as you say, make the world a better place.
I fear that students really believe their debt to society is making generally pointless noise while good deeds need to be done.
The only difference between service and activism is that really committed people do both while others take the easy way out and just talk. True activists get involved in both sides of the equation.
The intellectual side of activism is also deeply rooted in Christian and Judaic values. You will find that major policy changes had the sponsorship of religious leaders.