He's the first one to admit that he's crap, however he still makes money and still can pull the crowds in after all those years of performing.
he's says he's not a great singer, but he's doesn't care because look at the money he's making.
If he's that bad as some people make out then why is he still going.

And how many of today's performers would turn up at your door and ask for a cup of tea.
Because these two women said to him once, to come round their house for a cup of tea, and he did.

So that's entertaining the crowd.