if you only want standard dvd quality then only buy standard dvd in the first place.
if you like blu ray enhanced quality, why seek to destroy it by compressing the movies back to standard[/QUOTE]
I’m always a bit baffled at people replying as you have.
I own 1 BD player and yet I have multiple SD DVD players in the household. So, I buy a movie on BD for the better quality and extras and I can watch it on my single BD player. Alas, I also have numerous other people in the house who also wish to watch the movie but they aren’t trustworthy and aren’t allowed to actually touch the BD disc nor do they care about the amazing BD experience. So, I rip the movie and then compress to a DVD9 disc which can be watched on any of the DVD players in my househould. I own the original BD disc, I own all the players in the household, and the copy is never leaving my house. Fair Use.
It would be utterly illogical to reverse this and buy a SD DVD release and then up-convert for my BD player? That just makes no sense.
So, there is one very simple answer as to why someone would seek to destroy the enhanced quality. I also have to say that I believe a BD original that is down-converted as a movie-only backup on a DVD-9 disc can actually have a higher bitrate than the original commercially pressed DVD-9 release because the BD to DVD backup doesn’t contain the extra fluff and wasted space including extra audio tracks and whatnot.