Can't expect EVERYONE to like him. At least they didn't spit on him, like what they did to Nixon in Venezuela back in the day.
The important question is not whether Obama is well liked around the world, but do other leaders take him seriously, do they respect him? The evidence so far says, no. Obama's call for more stimulus spending by the developed world was largely met with derision by European leaders and his call for more troops from NATO for Afghanistan was largely ignored. At the G8, he spent most of his time apologizing for the US not being more like Europe, and at the end he sounded like a Miss America contestant breathlessly opining, "If I were President, I'd like to end world hunger."
Iran has repeatedly told him what he can do with his outstretched hand, and on his ME trip, both the Saudis and Egyptians lectured him and threatened to withdraw the Arab peace plan rhetoric if he didn't force Israel to to cave to Palestinian demands within two years, in effect, threatening to try to derail his reelection bid if he didn't do as he was told.
When Netanyahu refused to cave to Obama's demand to freeze all construction in the settlements, his approval ratings nearly doubled, and a recent poll showed only 6% of Israelis trust Obama to be fair and honest in dealing with Israel, the worst poll rating of any US president in history, meaning that US influence in the Israeli-Palestinian dispute is at an all time low because of Obama, and Abbas, whom Obama is trying desperately to keep in power when Fatah chooses new leadership next month and the PA holds elections early next year, has stated both he and Netanyahu are ready to beginning peace talks without preconditions, but Obama is demanding an end to settlement construction, and now an end to construction in east Jerusalem, before peace talks begin. Both the Chinese and Germans have voiced concerns that Obama's reckless borrowing and spending pose threats to the whole world economy.
Obama remains personally popular with the people in many parts of the world, but so far he has failed to earn the respect or to be taken seriously by other leaders.