They've gone over this pretty thoroughly a couple times now. You can search for it if you wanna know the specifcs but it boils down to that fact that a DVD can only hold approximately 2 hours of "video" format if it is going to be used in a DVD player. However, if you format the content as "data" opposed to video, then you have a full 4.7 gigs to fill.
Let's say each match is 4-5 minutes. On a video formatted DVD you could hold 24-30 matches, which is roughly 8-10 sets (3 matches per set).
Now let's take the alternative, each match is approximately 20 mb (?). This mean you could around 235 matches, roughly 10 times that the video formatted DVD could hold.
So they could have formatted it for a DVD player, but you really wouldn't want that.
edit: Neal beat me to it