In the context of North Sydney Tall Buildings, no, it's not too bad.Agreed, heritage alone is not warrant to give a building value. A city is not a museum and buildings must serve the present.
However, I would argue that this building provides us with a very good summary of mid-20th century modernism and will only be replaced with another 21st century example of post modernism or modernism. It's better to keep it.
It's not so bad.
I don't personally have a strong view either way, just wanted to counter the suggestion that a building can't be both a heritage building and an eyesore!
(In fact, it's often the same characteristics that make something 'an eyesore' that make it good for heritage status - check out Alexandra Road Estate in London, which is a Grade II listed building)