The one reason is the Middle East.
Why? How is the Middle East related to the Linkedin Background Image's design.
OK, I'll tell you.
I'm European, from Hungary (I didn't vote for V. Orban), we right from left to right while in the Middle East (I have a special bond to Israel) people write from right to left.
The reason is that if I want to hide something to a bunch of people but tell to little, I need to show that thing only to them.
Ask me about Linkedin, I reply since 2011
Follow the #LinkedinByTamas hashtag 🙂
#PeopleLoveDesign was not used on Linnked in back in January 2018, so I advsied a design team to use as their unique hastag.