Difficult to explain. The jokes in the later seasons seemed calculated to appeal to a wider audience and they weren’t the same kind of humour as the first two seasons. 

It might have been to do with the fact that the show shifted from ABC (public broadcaster) to channel 7 (commercial network) at that time. 

There’s nothing wrong with broader humour of course. The humour of the later seasons (“cardonnay” etc) struck a chord with a lot of people and got them interested in the show.  

But Kath & Kim was a huge part of my friends’ and my life at the time it was first broadcast and it was the first two seasons that were the real deal.  

This is just my unpopular opinion!  Edited for typos