Alright:
Superheros irresponsibly confront dangerous villans near a school.
Back it up.
They discover dangerous villans near a school, and (uncharacteristically) decide they can take them. They're discovered, because they bring a camera crew with them, and quickly lose handle of the situation.
What is characteristic, is property damage caused by superhuman fights between heroes and villans, and people die.
Moral of the story? Stupid heroes do stupid things, which get innocent people killed.
But people are mad at the heroes for no good reason, apparently.
I get that. However they didnt cause Nitro to explode. Nitro exploded on his own.The New Warriors didnt trigger him.
However, the rest of your post addresses something far different. To go in front of congress, they'd basically be making themselves vulnerable to scrutiny of their own, sometimes underhanded, acts themselves, and would definitely come off as pompous for going in front of congress behind a mask, and telling them how things need to be. Rather than NBA players defending their actions due to the stress of their sport. It's not really comparable.
Tony and Peter went before Congressial hearings on superhumans
Heroes, now united, are given a direction and support, and initiative they haven't exactly had before. Generally, when confronting a villan, they'll chase them down, beat them up, and help put them in jail, and wait for the next villan to arise, or get info on a villan. With the government running them, they're now given these tasks far more often, and pursue it in either the same vigor, or less than in many cases.