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. 
lol, like that 50% lead would ever have held and considering the barrages from the GOP and the Bernie obsessives (since it seems he can't keep his followers excited without going negative on and undermining Clinton) it's pretty impressive the favourables are where they are. And yes, she's still a better candidate.
