Was ENT a failure, yes or no?
Any good space opera will ride Trek's recent success but Trek was a failure on tv and that can't be built on unless you, CBS or Netflix has 75 million dollers to spend on every episode, bacause they - the movies and tv are two different animals.
I really don't see how you can call Trek a "failure" on TV, not with 21 seasons of live action overall, 18 of them consecutive.
TOS was a failure on the networks, but became a massive success in syndication, paving the way for four successor series and a dozen movies (counting the one releasing next month).
TNG was a sufficient success to lead to two spinoffs and a prequel series, and all the Trek series are making money through DVD, streaming, and merchandising.
That doesn't mean that the previous successes would be easy to replicate in the current TV environment, but the history of the franchise should not be considered show-stopper.
Seven hundred episodes is not a sign of failure.
The why doesn't matter right now. Berman is gone. I do think it is a perennial but not one that I'm interested in with JJ in control. I wasn't too interested in it with Berman in control. I don't think their syndication value will be as high as TOS especially as time goes by. ENT has already been attached to Trek 09 as some kind of alternate universe history which I have no interest in.
That's a different question than whether Star Trek itself was a failure on TV. As to the answer, ENT was a failure when judged against its expectations, and a success when judged against the majority of science fiction TV shows.
As for syndication value, today's market is so totally different that it's not really fair to compare any of the more recent series to TOS. When I started watching TOS in syndication, there was no other option available. Now you can get the shows on web streaming, buy digital copies, or even physical copies; none of that was possible when I was a kid, as the VCR hadn't even been introduced at the time. It was syndication or nothing.
Personal interest is a whole different issue, and not something that can be quantified. I don't mind JJ Abrams' Trek, but I don't have the same feelings for it that I have for the TV series. If pressed, I would say that I expect another Trek TV series at some point in the future, but I would not be surprised if it's not before 2020. I'm not saying that I'll necessarily like it, but I do expect it.
Star Trek works on TV (or the web), it was made for the small screen.