That would be like saying that all of the Titans that died in IC deserved to die because they took on a enemy that vastly outclassed them. and they stupidly rushed him. If heroes deserve to die for their mistakes we would be VERY short on heroes.
Without sarcasm I can say that I'm glad that Marvel wrote the New Warriors downfall so effectively that people are convinced by it. I hate what happened, but I'm glad that Marvel is getting back on track.
Why the Warriors? Why not the Slingers? Or the Young Avengers or even the Runaways? Simple, this version of the New Warriors fit perfectly into what would exarcebate the situation. Not only were they heroes that Marvel (possibly) considered disposable but still had some fan following to cause some kind of impact, they also had the media (tv) angle that would broadcast their mistake. Runaways/Young Avengers are making money for Marvel so they're not going to get rid of them although it would be more believable that it would've happened to them.
Why didn't Night Thrasher, who's a control freak, stop Speedball? The only characterization he was given was that he was offended by being called a dominatrix.
The attack went off perfectly and Nitro was the only "bungle". Like I said before, Nitro's explosion could have been of a lesser degree like other times when he has fought other heroes in populated areas. This was a setup and they were the scapegoats, simple as that. Personally, I see it as a disservice to the characters but I'm also aware that the New Warriors were very much a product of their time and this generation has their own New Warriors (Runaways/Young Avengers).