It isn't about image degradation, but that person trying to get the best picture possible.
DVDs have their picture encoded at 480i. Some scalers/deinterlacers do a better job than others. Also many players can not output video over HDMI at 480i, but a minimum of 480p.
If the inbuilt deinterlacer does a poor job converting 480i to 480p, no matter what you do to scale afterward isn't going to look good.
That was until ABT released their newest chip, which can take a 480p image which was created poorly and turn it back to 480i and do it right.
Really, judge with your own eyes, since you're the person which will be watching it.
