Why do some people litter when they are steps away from a garbage can? Why do some people play their phones at high volume on public transit? Anti-social behavior comes in all shapes and sizes.
There is a distinction between pro- and anti-social behaviors beyond capitalist and socialist systems. You can have anti-social behavior in both systems. You can have pro-social behaviors in both systems. This should be fairly straight forward.
Not accommodating someone disrupting a service does not mean we need to be absolute pricks about it. This happens every day in public libraries, public parks, public toilets, and public transit systems. Simple because a need exists, doesn't mean the library or transit system does not also exist to meet needs.
If you think that socialism -- alone -- will end homelessness, I would ask you to check your history books. There was homelessness and vagrancy in the USSR. There are plenty of folks in San Francisco who refuse shelter when offered: https://x.com/LondonBreed/status/1734350588899717423 ... we are currently experiencing a move in large parts of the west from high-trust to low-trust societies. Much of the issues around homelessness, lack of housing, and refusal to provide adequate shelter space stem from folks engaging in low-trust behaviors, treating property as a zero-sum good, and cities as places that should exist in a type of stasis... rather than as communities that must continuously grow and change to meet needs. These low-trust issues certainly can persist in low-trust socialist societies as well.
The USSR did massively reduce homelessness by providing homes. They discovered the surprising fact they if someone has a home they are not homeless.