If TV was all that the ABC and SBS are, you may have a point. I don't agree with everything that all of their presenters say. I'm on the right of centre politically and economically, so please don't say I'm a leftie, but I cringe at the alternative radio stations. At least I can intellectually disagree with the ABC presenters.
They have a website which is probably second to none for news.
They have radio and television stations and their radio stations are also varied.
They may well be on the left of centre, but at least those left of centre offer an intelligent, if biased, argument.
And Petro is correct that you wouldn't get the quality of television without the ABC.
Then there's SBS.