Punk as we knew it is dead. Scenes like the hardcore scene is alive and well though. There still tons of bands that have huge followings all over the world. Most cities do have underground scenes that still have the same ideologies about music that they did when the music first came out and will support the bands touring through.
What you are confusing is the mainstream view of punk and the underground view of punk. When punk/hardcore punk fist came out it wasn't ever the bands intentions to get famous or radio play, they just wanted to get together with others that thought critically about what was going on in the world and express views through song. In that case, some traces of punk still exist but more through hardcore these days.
The problem is Mainstream music who want record sales and to make as much profit as possible. They needed to find new ways to market music and they chose punk because there was a market for it that already existed for it. So their lack of imagination simply placed the bands you are talking about under a "punk" umbrella and sold it as such and because people would buy that crap and they will continue to buy more of the same. They are too stupid to notice the difference. Its not punk rockers that labeled the bands your talking about as "punk" it was the greasy record executives that did. Those bands will continue to shut up and and do what they are told to preserve their image. I have no respect for that garbage and refuse to listen to it.
There is still great punk and hardcore out there you just have to find it unfortunately you have to sift through the *** labeled as punk first.
Spreading The Hardcore Reality