Parties as vehicles for activism are not fashionable. Citizens are also better informed than was once the case, the media have played a critical role here. Public demands on government are greater and more divergent. It is difficult for parties in government to satisfy these demands responsibly. Parties are lumbered with the burden of governing, non-party activists are not.
Parties are basically electoral colleges, their job is to elect candidates for public office.
They have won this privilege through a century or more of organising elections and maintaining loyalties based on class, religion and ideology. These divisions are now much weaker, old loyalties can no longer be relied on. Parties do not make policy, politicians do, often at the behest of interest groups and experts, and always with an eye to the electorate. The parties barely exist without public funding and politicians and their staff. The Democrats argue that the Australian Electoral Commission should conduct internal ballots, as they do for unions and employer associations.