I'm in the process of reading the book as well and I agree with what Zaid Hamid has to say here. ISI is just doing its job. Intelligence agencies work in the shadows and engage in extra legal behavior to protect the country's national interests, so why not ISI?
Steve Coll is a noted journalist and his book is well researched and documented, including interviews with many Pakistanis. You may disagree with his conclusions, but doesn't make him a 'scumbag' or has an ulterior motive.
From what I've read so far, the book actually clarifies Pakistan's position on Afghanistan and ISI's role in it. If anything, it makes the US looks even worse. The war in Afghanistan was half-hearted, at best, the Bush Administration was more keen on invading Iraq than destroying Al-Qaeda. Then there was the mission creep of nation building that has gone arye. Afghanistan is no more being a nation than it was in 9/11, arguably even less so.
In essence, US has no idea what it's doing in Afghanistan, no plan, and no exit plan.
I agree. It should read why US failed in Afghanistan and will continue to fail.
The article was for Indian audiences, so don't worry if he's failed to convince you. It's Pakistan's failure to convince the world otherwise. As for the book, it's natural Pakistanis will hate it, but it wasn't written to convince them.