The platform seemed to be based on some weird 'forms' based application builder when it was released ten years ago. It is flakey as hell. Ugly I can deal with, we have ebay and it still works fine, but even the most basic things you would expect, for example when you press tab the cursor to follow the order of forms on the page, does not work. Often when you submit a form the focus ends up on some text field.
The integration with other services, such as Medicare, barely work. I have spent endless calls on the phone to near useless support staff trying to get emails reset for old mother. The support staff are friendly but don't seem to have any ability to do anything but reset things that take several hours to complete.
The tax and business functionality is completely senseless. They got the paper forms designed in the 50s for batch mainframes and coded them into web forms. You have to do things like copy the same value into multiple fields marker T8 and T2. The instructions say just that: "Copy the value from T8 to T2". If you don't it fails.
The article mentions the huge problem with them having no in-house expertise so they bring in consultants. I work here in Sydney and I know, from first hand experience working with them, these large consulting companies have the same or less technical expertise. What they do have is huge sales teams and even larger teams of project managers. The odd technical person they have is spread across so many projects they are pretty much useless. They employ hordes of off-shore developers that are managed people with little or no clue about anything.