If we're all being honest without ourselves, there aren't a lot of reasons to hate Kwame Brown. You can be upset with how his time in Washington played out after the Wizards took him with the top overall pick in the 2001 Draft, but hate is such a strong emotion to direct toward someone whose worst offense was being an 18 year old Michael Jordan thought he could craft into the next Horace Grant.
No, most Wizards fans don't really hate Kwame Brown, they're just sad about Kwame Brown. Sad that he didn't live up to expectations.