I understand the argument about owning media for sure. However, until the movie studios sort themselves out about owning/renting something online and being able to watch it consistently in multiple places I will likely still buy certain DVDs for awhile. Amazon VOD for example is available on my Roku in one room but not on my PS3 in the other.
With young children in the house (I have three) I will still be buying media pretty often on DVD and/or Blu-Ray to be able to move it around to all my DVD devices - cause they like to watch things over and over. Not to mention in the mini-van on the portable DVD player
Take a movie like "Looney Tunes Back in Action". Its not a very good movie, but my kids fell in love with it on Netflix Streaming. Well, a few months ago Netflix apparently lost the rights to stream it anymore. They still ask to watch it, so now I am into going to go find it on DVD to be able to have it around for them. I wouldn't buy a movie like that on Blu-Ray cause it is just for the kids and is old. Take a movie like Toy Story 3 though. I looked for a good deal on the bundle - Blu-Ray/DVD/Digital copy all in one and bought that. Blu-Ray goes in the PS3 and it looks simply amazing on my TV. Better than any of the streaming services are offering and offers many extras besides (additional cartoons, behind the scenes, etc..) that I am interested in. Reg DVD goes in the Van, and digital copy is on my iPhone/computer. That was worth the $20 I spent on it to me. Same story with Star Trek (the 2008 film). I like the way it looks on Blu-Ray. Also when it comes to certain TV shows the wife likes to fall asleep to them, so she will put in something like 30 Rock and set the Blu-Ray to "play all episodes" and it will play for a few hours while she goes to sleep. Netflix doesn't yet offer this. For some older movies destruk I think you are right to question the value of Blu-Ray, but for certain movies -I'd argue Toy Story 3, or the more recent Harry Potter films as examples, Blu-Ray is a considerably better picture if you are using all HD equipment to view it.
That being said, I buy a lot fewer
discs than I did before the streaming services came along - and I am a big fan of them.
My parents on the other hand almost never watch DVDs... so I think your experience with your parents stratcat may be something to think about. With Netflix and a video rental service like Amazon on a Roku my parents would likely never invest in any Blu-Rays anyway.... hmmmmmm.... My mom would just stream "Say Yes to the Dress" off Netflix 3 hours a day.
Another aspect is the constant adding of new channels and the flexibility Roku gives to programmers to create private channels. A webstreaming blu-ray player isn't going to match that.
Edited to add - some of you were posting awesome points while I was writing this reply! Tell me more of this iphone/ipad streaming to private channel!
Roku XD/S purchased in Dec. 2010