and arent' there retro-active device blocklists on bluray? I seem to recall sth of the sort. Sure, they can be circumvented, but then why bother buying in the first place if you're gonna be the bad guy anyhow?

Yes and yes. I got mildly upset when I learned this, because it is oddly surprising amount of work to get it to work ( and some models do better than others, apparently ).

On the other hand, dvd is dirt cheap now and you get a very respectable collection that is not reliant on the internet.