Why does the Protobuf JavaScript compiler suffix collections with "List", "Map", etc?

Question

Why does the protobuf JavaScript code generator suffix collections with the collection type?

For example:

• repeated string names becomes obj.namesList
• map<string, string> bar becomes obj.barMap

And this is as per the documentation, here: https://developers.google.com/protocol-buffers/docs/reference/javascript-generated#repeated

Why is that?

It makes life difficult when using grpc-gateway with --swagger_out because the swagger API definitions don't match the generated JavaScript.