1 To protect intellectual property
The intellectual property is considered to be one of the most crucial things for all webmasters. That's why they disable the right click to protect their intellectual property, which can be in the form of images, text, or source code.
2 To prevent image downloads
Webmasters do not enable right-click on their websites, especially for image-based websites, as they do not want anyone to download or copy their website's images.
3 To prevent content copying
Some people disable right-click to restrict anyone to copy their website content.
4 To avoid the extraction of direct links
If the right-click is disabled, no one will be allowed to extract the direct links mentioned on your website.
5 To ensure the security of the site
Some webmasters believe that impairing the right click improves the security of the site. Maybe those webmasters are not aware this security measure can easily be evaded.
6 To avoid re-submission
Sometimes the site gets reloaded by mistake, unintentionally. This increases the resubmission errors; however, if the right-click is immobilized, it cannot be reloaded.
7 To make it look secure
Some government or private institutions may disable the functioning of the right click as they want the site's users to fall under the impression that the site is secure.