Why by enumtype dynamic="false" is set to false?

Why by enumtype dynamic="false" is set to false? And when should I set it to "true"?

<enumtype code="MyEnumType" generate="true" autocreate="true" dynamic="false">
    <value code="NONE" />
    <value code="ONE" />
</enumtype>

In simple words, I can say static enum(dynamic="false", default value) is generated as the Java enum. In which list of values can only be changed during compilation time by changing the items.xml. In case of the dynamic enum(dynamic="true") we can change(add/remove) its values at runtime using hmc or Impex.

Static Enum:

    <enumtype code="FixedValueType" autocreate="true" generate="true">
        <value code="value1"/>
        <value code="value2"/>
    </enumtype>

Dynamic Enum:

    <enumtype code="OrderStatus" autocreate="true" generate="true" dynamic="true">
        <value code="CREATED"/>
        <value code="ON_VALIDATION"/>
        <value code="COMPLETED"/>
        <value code="CANCELLED"/>
    </enumtype>

more about hybris enum