"Oh wouldn't we all like to see your reaction if you happened to be placed in a situation such as these officers found themselves in?"
Why should that matter? None of us has had training (or at least, most of us won't have) in how to arrest someone, and yes I expect very few have experiences that even come close to that. But broadly the point remains that the job of police is to bring criminals to justice. That means, ideally, alive so that they can face trial. Certainly for such a petty crime as this there is no reason for them to end up dead. As far as I can see from the video, he "resisted arrest" in the loosest possible sense before the officers jumped on him, and it took them barely five seconds, tops, to decide that this was only possible with a dangerous method of restraint that put the man's life at unnecessary and, ultimately, fatal risk.
At best, this smacks of poor training and awful philosophy. Regardless of whether or not I would have done the same (I wouldn't have, but then I'm a weakling and would struggle to win fights against sick flies), the police in this case failed in their basic duty and took action that was far too aggressive and resulted in a man's death. That no charges were brought is, indeed, astonishing. I would hope that at least the officer in question will be disciplined internally.