Is it me or does “bittersweet” seem like a very odd (and inappropriate) choice of words?

Via Politico:

Vice President Joe Biden drew on the sorrow of his own personal losses as he addressed the memorial marking 11 years since United Airlines Flight 93 crashed into a Pennsylvania field.

“It is a bittersweet moment for the entire nation,” Biden told families, friends and dignitaries gathered at the memorial to the 40 passengers and crew who died on Sept. 11, 2001.

“We wish we didn’t have to be here, wish we didn’t have to commemorate any of this,” he said, drawing on his own sudden loss, when his first wife and young daughter just before Christmas in 1972.