Do you want to become a involved in drupal? There are a couple of ways to get a drupal job. The fastest way to start get a drupal job is try and find someone who can show you around. If you have been to drupal.org you might feel a little overwhelmed. The whole drupal universe is big, very big and it is difficult to figure out what you need to do and even more important what you want to do.
If you want to create a custom views access plugin the reason for this will be to allow you to have an entry point to add custom logic to protect the access to your view.
Let say you need a finer access control to a view than roles and permissions. For example you are storing properties on a user object who determine if certain user can see certain views independent of their roles.
What we need to do, is to configure our views correctly with a views access plugin.