The Urban Outfitters Company made a sweatshirt based on the death of four students several years ago. For the families of these students, it is easy to see why they would probably feel that the company is making a quick buck off of their losses. There are a lot of other non-offensive designs that could have been chosen instead.
People died at Kent State. The shirt created by Urban Outfitters was clearly designed to draw attention and shock the audience. It is offensive regardless, but it is made even worse by UO's clear attempt to be offensive. A 9/11 shirt, or something making fun of Newtown, Connecticut is probably UO's next step.
What else could the Kent State sweatshirt have meant other than to reference the terrible things that happened at Kent State during the Vietnam War? They did not make a sweatshirt with red spots on it for any other university. It had to have been what they meant. It is terrible that they are now claiming it was an accident.
Looking at the shirt it's difficult to believe that anyone couldn't take it as a blood spattered design. Their claim that it was intended to be 'vintage' seems unlikely. However, the shootings were over forty years ago. It was a horrible, tragic thing to happen - but not recent enough that a sick joke would even be recognised by most people. Because of that, I think we have to give them the benefit of the doubt this time - why would they have told a sick joke that people wouldn't understand?