Wordpress gives you the opportunity to create a basic structure blog site or ecommerce relatively easy. Let's say "with the press of a button" sort of speak. This was the first CMS i ever touched, but then i saw the difference in speed, database structure and flexibility that Joomla! gave me, without the need of using 5000 different plugins.
At first it was not easy to understand that because i was trying to learn a new CMS and coding at the same time and i got frustrated. But i am happy that i stayed with Joomla! (and coding of course). If you have the patience, Joomla! will teach you a lot, especially now that 4 is stable. I've built 2 e-shops on it (Hikashop) and i really enjoyed it.