What is the significance of antinode at r=0 in the plot of radial wave functions of s-orbitals?

![enter image description here](https://i.stack.imgur.com/WUpgd.png)
Why should there be an antinode at r=0? 
I can comprehend the presence of node at r=0 for p,d,f orbitals; but I don't understand that of s-orbital. 
Is there any intuitive approach?


