That being said, give Murray a 2-3 slam year and most of these "haters" will quickly hop on the bandwagon. They are easy riders who latch on to a player once he becomes the best. They are not the kind of people who would stand by a player thick or thin, or support said player while he struggles to emerge; they measure character by number of victories and deride as weak and lazy a player that is not a success. Gloryhunters through and through. How easy it is to glorify a champion after the fact.
Look back on Djokovic-related threads from 2009 through 2010 and see the extent to which he was derided for his personality, for being a choker, mentally weak, etc. Then 2011 came and he began crushing Nadal, and he was proclaimed a hero, champion, mentally strong, etc.
There is no objective fact about Murray or Djokovic (at the time) that garnered enmity, just excuses people created to hurl invective at those they perceive as weak. Sort of like the Roman audiences cheering on a lion mauling a slave in the coliseum. When that slave happens upon a spear and impales the lion, the same crowd that was hitherto enthusing the slave's death now showers him with applause and praise.