As problems go, that's a relatively simple one that they ought to be able to address. The ascent appears to have been successful (though for a few moments it looked like something caught on fire and I'm not sure if that was planned or expected). The glide worked. The rocket was able to navigate to the landing pad.
Next time they'll be working with a lot more information. This seems like overall it was a success, even though they're down one rocket and three engines. A failure would have been the rocket blowing up on the pad during launch or other similar mishap from which they wouldn't have learned much aside from "make sure that doesn't happen again".
Good thing you aren't the one designing these things.
The primary objectives of the test were completed without any issues. If that doesn't meet your definition of success, I don't know what to tell you...
Even if this model had worked perfectly, it's unlikely they ever would've flown it again. Remember, SpaceX's goal is to mass produce these.
Much better to fail hard now and in many different ways, as the more problems you can find with your expendable prototypes the better (before your manufacturing process starts to ossify).
News anchors? They're often pretty clueless about technical things, so their mistakes don't mean much.
https://en.wikipedia.org/wiki/Mercury-Redstone_1
Technically the Shuttle go or blow moment is when the SRBs are turned on.
But yes, otherwise in the spirit, it will either blow up or be generally sucessful.
They didn't stick the landing, but it looks like they got test data from all the planned test activities. The explosion will prevent gathering some data from post-flight inspection, but other than that I doubt it has much affect on future development.
To look back on SN5/SN6 testing, they stuck the landings with those prototypes, but the prototypes themselves are now obsoleted by the new prototypes in production (up to SN16?!)
Seems to be a great benefit of this method that SpaceX is following with Starship: if you build hardware fast and cheap enough, you can afford some partial failures since you just put the lessons learned into the next flight in a few weeks.
And as others have said, it's either complete success-or-explosion that's expected in this area.