Osama bin Laden did not attack Reddit. There is no credible information or record that bin Laden ever attacked Reddit as a platform. If the question is about why Osama bin Laden attacked the United States, as in the case of the September 11, 2001 terrorist attacks, the reasons were based on a complex set of grievances and ideological motives. Bin Laden and al-Qaeda targeted the U.S. because they viewed the U.S. as a symbol of Western influence and military presence in the Islamic world, especially citing issues such as the presence of U.S. troops in Saudi Arabia, U.S. support for Israel, and what they saw as oppression of Muslims worldwide. Bin Laden expressed these motives in various public statements and letters, framing the attacks as acts of jihad to defend Islamic sanctities and free Muslim lands from Western domination.
To summarize: Osama bin Laden attacked the United States, not Reddit, and his attacks were motivated by political, religious, and ideological goals against U.S. foreign policy and presence in Muslim countries.