why are they still doing these
Because Clinton has failed to clinch the nomination yet and it's almost June lol.
Obama did not clinch the nomination while running virtually unopposed in 2012 until sometime in April. Romney didn't clinch it until June of 2012. Trump has yet to clinch it.
#Math
It's called having a 50+ point lead a year ago and blowing it, the comparison you use with others is completely irrelevant. Also this same poll has her unfavorables at 59% and Bernie's at 43% but yes she is obviously the better candidate.