Developers who will make use of OOPs concepts heavily,like JAVA/Spring/Oracle PL-SQL people,they say that PHP language itself is used for presentation/view/display logic in the Enterprise level projects.
In these BIG projects the backend is Oracle,the database is fetched using pl-slq/java and presentation is php.The best example is facebook.http://en.wikipedia.org/wiki/Facebook
facebook uses php for presentation, java/c++ as backend interface.
The only reason php is used as presentation because it works closely with HTML,but java/c++ is more OOPs based and can't be fit directly with HTML.
Tell me one CMS(joomla/drupal/wordpress) or framework(zend/symfony/Yii) which makes use of Smarty? So WHY smarty is necessary?