So why not use XML::Simple?
Because the module author advises against it. From the XML::Simple
POD (STATUS OF THIS MODULE):
The use of this module in new code is discouraged. Other modules are available which provide more straightforward and consistent interfaces. In particular, XML::LibXML is highly recommended.
The major problems with this module are the large number of options and the arbitrary ways in which these options interact - often with unexpected results.
Patches with bug fixes and documentation fixes are welcome, but new features are unlikely to be added.