"Hey COURTNIE!"
Imagine everyone had to yell her name when addressing her! Or equally as weird, now that everyone is a DJ, what if when addressing someone it had to be by their moniker?
For example:
Mother: Violent J, your soup is going to get cold.
Jeffrey: I'll be there in a minute!
It's not a practical way to live. This is why Shakespeare invented names that start with a capital and leave the other letters to just chill.
Shout out to the other letters, you're totally special too.