customerConverter and customerPopulator problem

In this trail link

https://wiki.hybris.com/pages/viewpage.action?pageId=294094311

we come across a stage wherein we add customerInternalpopulator to customerConverter list

Then why isn't the customerPopulator added in same way to customerConverter as above, but is done as in code snippet shown from commerfacades-spring.xml(line 590 to 607) below

 <alias name="defaultCustomerConverter" alias="customerConverter"/>
         <bean id="defaultCustomerConverter" parent="abstractPopulatingConverter">
     <property name="targetClass" value="de.hybris.platform.commercefacades.user.data.CustomerData"/>
             <property name="populators">
                 <list>
                     <ref bean="customerPopulator"/>
                 </list>
             </property>
         </bean>
     <alias name="defaultCustomerPopulator" alias="customerPopulator"/>
     <bean id="defaultCustomerPopulator"
             class="de.hybris.platform.commercefacades.user.converters.populator.CustomerPopulator">
         <property name="currencyConverter" ref="currencyConverter"/>
         <property name="languageConverter" ref="languageConverter"/>
         <property name="customerNameStrategy" ref="customerNameStrategy"/>
     </bean>  

Let me summarise ....why isn't it like this??

 <bean id="customerPopulator" class="de.hybris.platform.commercefacades.user.converters.populator.CustomerPopulator"/>
    
    <bean parent="modifyPopulatorList">
    <property name="list" ref="customerConverter"/>
    <property name="add" ref="customerPopulator"/>
    </bean>