The author made an implicit assumption, and you're making the same one, that they're filled with wisdom received straight from al-Ghazali. Firstly, only wankers act like they're wise and their audience isn't. Secondly, they said "haven't read al-Ghazali yet", implying that it's only a matter of time before everyone reads him.

Lastly, it's fine to quote someone but you need to explain how it's relevant to the conversation. The author could have summarised al-Ghazali's idea about free will or whatever and it would have been fine. But he didn't even bother, as if the ideas so basic and well known that it's not even worth doing.

I'm pretty comfortable with the way I've poked fun at the author's pompousness. If you need further explanation it's because you haven't read Chanakya yet.