Never.
"Neighbours" has become a wonderful institution.
Whatever the show's detractors may say, there are a few important things to remember. It regularly attains a bigger audience than other imports such as "Desperate Housewives" and "Lost". It also attracts a larger audience than some UK soaps on occassion, including "EastEnders". Given it's time slot, that is incredibly impressive.
Secondly, the show has never tried to be "hard hitting". The programme is not concerned with dealing in larger social issues. In avoiding this, Neighbours is probably a far more realistic representation of everyday life. As much as it tries, "EastEnders" is not the "gritty" portrayal of tough lives it claims to be. For a start, nobody in London (or indeed the world) speaks like Pat Butcher - what the hell is that accent they speak in Wallford?
I'm currently studying Television. I deal with complex, yet often greatly flawed programmes that take themselves too seriously every day. "Neighbours" is my idea of heaven - it's an unpretencious show that just focuses on simple storytelling, oh; and the sun is always shining.
I love the characters and the innate charm and innocence of "Neighbours". Give me that over all the UK soaps any day. And I tell you what, this show isn't as silly as it might look. Sometimes a work of genius doesn't have to be complicated.