Why using a 0 value resistor
People use zero ohm resistors for several reasons: -


To act as a bridge to isolate ground planes or power planes.
To preserve the ability to insert a non-zero-ohm resistor should optimization of some parameter be required.
To ensure that a test point is positioned electrically where it ought to be.
Unused digital input pins instead of terminated directly to ground are often connected via a resistor or zero-ohm-link so that if needed there is some copper with which to make a wire connection to.


There are probably other reasons too. Take your pick.