Nothing prevents governments, ISPs, your school or work, etc. from blocking Bitcoin network connections. However Bitcoin is decentralized, there are no servers or clients, only nodes. So in order to "kill" Bitcoin, you would have to prevent every single node from connecting to any other node in the network. This would have to be a worldwide effort since Bitcoin nodes can be found all over the world.
Furthermore, Bitcoin does not necessarily have to rely on the internet. There are projects that are working on providing non-internet means of communication for nodes, such as Blockstream Satellite.
To me a node is a TCP end point connection, server is just a generic term. If I am in the US I can only connect outbound through the network routers. If our congress passes legislation such that every router in the US must block the bitcoin port, any outbound TCP connection from me how would my TCP connection request ever get to a distant node, outside the US. No matter how you look at it my device is a client to something if it sends a connection request. I understand that US regulation would not effect distant nodes but, how would my connection request ever reach one. I don't trust what is going on with our government and I have a feeling the bitcoin movement may be underestimating this power.
As far as not having to rely on the internet, I get you point but what is possible and what is now are different issues.
