White people. Explain this nickname nonsense

[xXOGLEGENDXx]

When us nikkas have a name like Ciara, we call her Cici which makes sense.
Nicole = Nikki. David = Dave which all make sense.

But white people call a guy named James, Jimmy or a Richard gets called dikk
John gets called Jack
William is called Bill
Robbert is Bob
Edward gets called Ned or Ted
Etc...

I don't get it

 

[STFARN]

Thats old school shyt

Long gone are the days of the Richard "dikk" Shermans or William "Bill" Pudnarski

RIP