It's kind of surprising people still donate to Red Cross, given their extremely poor track record. I suppose they have brand name recognition. South Park had a great jab at them, with all the 9/11 donations being stored away in an Indiana Jones lost ark style warehouse.
IMO, a nice chunk of donations are done so people feel better. "Everyone" likes Red Cross so a donation there is seen as safe so it's the easiest path.
I wouldn't go that far - companies partner with The Red Cross left and right after every major disaster, and the mainstream media downplays the problems with the organization. For the average person, there's no reason to suspect that they'd be misusing/misappropriating funds.