The article names 3 of the 100 organizations to which Soros donated -- the Center for Reproductive Rights, MoveOn.org, and the Human Rights Campaign. These are traditional liberal charities, and it is not at all surprising that Soros donates to them.
I'm not surprised he donates to them. However, when people donate that much money to a political cause, there's usually a reason beyond mere benevolence. For example, Bob Perry donated colossal money to political organizations in Texas, and in return, they pitched his policy agenda and backed candidates who would do his dirty work.