Magento 2.0.2
File :- vendor/magento/module-catalog/view/frontend/layout/catalog_product_view.xml
block :-
<block class="Magento\Catalog\Block\Product\View\Attributes" name="product.attributes" as="additional" template="product/view/attributes.phtml" group="detailed_info">
<arguments>
<argument translate="true" name="title" xsi:type="string">
More Information
</argument>
</arguments>
</block>
I am overwriting this block in my module with same file name like this (by action method) and it is working:-
<referenceBlock name="product.attributes">
<action method="setTitle">
<argument name="title" xsi:type="string">Product Details</argument>
</action>
</referenceBlock>
But when i updated this title by this below method (argument menthod) it is not working:-
<referenceBlock name="product.attributes">
<arguments>
<argument name="title" xsi:type="string">Product Details</argument>
</arguments>
</referenceBlock>
So, my question here is that why it is working by first method, as it is mentioned in documentation that it is not a recommended way to modify block arguments link