Disabling highlighting and right clicking is common in some places in East Asia such as Korea. As to why this is done I have no idea. Especially since you can

Disabling highlighting and right clicking is common in some places in East Asia such as Korea. As to why this is done I have no idea. Especially since you can circumvent the disabling of these abilities. Although you have to resort to OCR when a site decides to render the text as an image.