The destruction of the Odyssey just seemed to me like a "Hey fans, we're NOT GONNA BE LIKE TNG". More a statement of what the show is not than what the show is.
Right. And it wasn't a reversible time anomaly or something like, say, "Cause & Effect" or "Yesterday's Enterprise" (though both were enjoyable eps in their own right nonetheless). I had the same feeling about later eps of DS9 like with Dominion War, as well as the new JJ Abrams Star Trek movie. The instant they destroyed Vulcan in that movie, I knew that we were in for some serious stuff and that they weren't going to pull any punches. At that point, it was made clear that nothing nor anybody is "safe" in the new series. I ALMOST thought that they were going to push a "reset button" at the end of the movie when they destroy the Narada and almost get sucked into the Black Hole but they didn't and for that I was thankful.