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.
The hacky way: