Nobody hires in one narrow field anymore, at least not according to the job ads. You need to show competence with six to a dozen different technologies from the basics (languages, server software) to the specifics (frameworks). Miss one and you're out. Have you worked with a CMS but not that specific CMS? You don't qualify. Have you lots of experience with several similar languages but never used this specific language in the workplace? You don't qualify. Are you an expert in the previous version of the language but you haven't caught up with the changes in the latest version? You don't qualify. Someone else evidently does because the company closes the position.