paragraph: During this time, Alexander adopted some elements of Persian dress and customs at his court, notably the custom of proskynesis, either a symbolic kissing of the hand, or prostration on the ground, that Persians showed to their social superiors. The Greeks regarded the gesture as the province of deities and believed that Alexander meant to deify himself by requiring it. This cost him the sympathies of many of his countrymen, and he eventually abandoned it. A plot against his life was revealed, and one of his officers, Philotas, was executed for failing to alert Alexander. The death of the son necessitated the death of the father, and thus Parmenion, who had been charged with guarding the treasury at Ecbatana, was assassinated at Alexander's command, to prevent attempts at vengeance. Most infamously, Alexander personally killed the man who had saved his life at Granicus, Cleitus the Black, during a violent drunken altercation at Maracanda (modern day Samarkand in Uzbekistan), in which Cleitus accused Alexander of several judgemental mistakes and most especially, of having forgotten the Macedonian ways in favour of a corrupt oriental lifestyle. Later, in the Central Asian campaign, a second plot against his life was revealed, this one instigated by his own royal pages. His official historian, Callisthenes of Olynthus, was implicated in the plot; however, historians have yet to reach a consensus regarding this involvement. Callisthenes had fallen out of favor by leading the opposition to the attempt to introduce proskynesis. 
question: What cost Alexander the sympathies of Alexander's countrymen?
answer: Attempting to introduce proskynesis