Yes, because he's Harrison Ford, and it's a movie. He's playing a character that's supposed to be an iconoclast... who is supposed to stand out and be the center of attention in an era where everyone around him was dressed well. To put an outfit like that together would require very high end components and a perfect eye to not look like a shitty high school prom rental. A guy wearing a white DJ in this day and age is going to stand out no matter what, so you might as well just keep it conservative and play by the rules.
I mean, there are plenty of times a see a photo of someone and think, "that's looks great", but then think twice.... "it looks great on that person in that situation, who had a small army of professional stylists and makeup artists attending to him, but probably would not work as well on me at XXX's wedding reception (or whatever)."