The following article contains spoilers from Dark Crisis #2, on sale now from DC Comics.
Deathstroke used his assault on Titans Tower to mock Nightwing and his lackluster students. His words and the students' reactions in Dark Crisis #2 (by Joshua Williamson, Daniel Sampere, Alejandro Sanchez and Tom Napolitano) prove that his assessment of the next generation of heroes is right -- they are subpar in comparison to their predecessors. Their composure during the attack and how they behaved in the aftermath only cemented that they aren't ready to be heroes, and it's even debatable if they ever will be.
However, there is a flip side to this argument. Deathstroke once again pulled out his most pathetic tactic and attacked children. Children who were in training no less. His beliefs about them may be based on the unfair advantage of the experience he had over all of them.
But he wasn't entirely wrong about their response to his attack -- one sneak attack and their entire infrastructure crumbled. What makes it even worse is that this is the second time that Titans Tower has been destroyed in such a manner. Apparently, both students and staff have learned nothing from their prior experiences.
On top of that, what the students did to counter this attack, was less than ideal. To say they didn't really put up a fight would be an understatement. They practically let most of Deathstroke's forces carry them away to be used as hostages. Not even attempting to put up a fight, they instead called out for their teachers to save them. Granted, they are still minors, but they have been training for months, which makes their passiveness absolutely inexcusable.
After the danger passed, a few of the New Teen Titans chose to quit being heroes, when their predecessors would have rallied. All it took for them to throw in the towel was Deathstroke saying that being a hero was now a death sentence. This further proves their incompetence and lack of motivation -- a real Titan doesn't quit, even when under duress. The instant resignation of some students calls into question whether they would ever be capable of becoming heroes at all, even without the undue stress of an ambush.
However, in their defense, it is not fair to compare students who are in training to heroes who have been doing this for years if not decades. Nor is it fair to stack them up against villains as terrifying as Deathstroke and not expect some sort of breakdown. After all, Deathstroke no doubt had the upper hand. He destroyed their base, separated the team, captured most of the staff and students, and would have killed Nightwing had Superman not helped him out.
Adding to this, Nightwing and the other teachers have been trying to keep the students out of harm's way while teaching them. It is a new approach, giving them a safe foundation to work with instead of throwing them into danger. But this has come at the cost of real experience, and as proven, the lack of preparation in the face of danger, which arguably is more dangerous than training them out in the field. However, regardless of their circumstances, their response to the attack and reaction in the aftermath was shameful. Their actions drove home how poorly suited these students are for being the next generation to protect the world.