Contrary to what some believe Elena hate is not from shippers alone. It is also not the actress or her personal life. As alot of people who hate Elena love Katherine and at least respect Nina.
The writers have damaged Elena, most likely, beyond repair as a character. The constant making everything about her was a bad idea. At first it was barely noticeable, but they kept going there until it was noticeable. Bonnie was missing all summer. No one knew until Jeremy came clean. Elena doesn't answer her phone for two hours and everyone is up in arms. You can google Elena hate and get a list of reasons. This is not just the wiki, it is most of the fandom.