Request: Setting "Atribute is required" without setting a default value

Setting "Attribute is required" and setting a default value should not be linked when creating a new attribute.

2 examples:
When using attribute in new issue:
if an attribute is date/time: setting any default value leads to errors if the attribute stands for deadline.
There should be not default value until new issue is created

if attribute represents a telephone nunber: setting xxx-xxx-xxxx as default value leads to closing new issue without setting correct value