The problem with Turnbull appears to be that either:
1) He has to balance his rather more radically right wing members of his party while keeping his further centre members happy else he loses his position. (Many peoples explanation).
or
2) He has significantly changed his opinions and position on many issues over the last 5 years.
And this is a problem because people cant really tell which it is.
Turnbull hasn't really changed many of the policies of his predecessor, he just wraps it up nicer and in a more statesman like fashion.
He was previously a more moderate right wing (by australian standards) but has since gone significantly more right wing.
Im not going into specifics because I don't want to go beyond the realms of the overall topic and end up talking about Gonski or something, but thats my take on why people are a bit bemused by Turnbull and not particularly forgiving despite his inheritance.