WordPress is a free and open-source blogging tool and a content management system (CMS) based on PHP and MySQL… WordPress was used by more than 23.3% of the top 10 million websites as of January 2015. WordPress is the most popular blogging system in use on the Web, at more than 60 million websites
What we learn from this is that many people can use WordPress, even without being PHP experts, and since it’s an open source CMS, anyone with some basic internet skills can use WordPress to build websites. However, that certainly does not qualify them as WordPress developers. In fact, some WordPress opposers often say that WordPress has lowered the standards of web development, imposing a situation where the true experts are no longer as needed as they were in the past:
WordPress development is a profession that is based on the infrastructure of PHP programming, but furthermore, it requires a deep understanding of the WP core, library and other common practices to produce great WP based products. Developing cutting edge WP Plugins or themes, and making them work properly in all environments while overcoming basic conflicts with popular themes and plugins needs vast amounts of WP knowledge, and a good amount of PHP skills, which are often underestimated by the common WP user.