It's possible to estimate the number of illnesses and deaths that the extra pollution would cause, and it's been done too:
http://www.theguardian.com/environm...ons-estimated-to-cause-59-premature-us-deaths
But the number of injured/dead isn't the only way to gauge the level of injustice. There's also the blatant and intentional disregard for the law, and the lives harmed. On top of that, the completely contrary marketing messaging of the affected diesels as 'green' to deceive the public has ratcheted up the sense of injustice even more. For all these reasons, it's completely unlike any recall that has come before it, and possibly far worse than any of them.
As for "fart in a windstorm", that could be used to describe any murder as well, since about 1/4 million people die every day.
The point comes down to whether one believes in the value of having NOx restrictions or not. Consider Beijing and Mexico city. Or any North American city in the 70s. I'll take my emissions controls, thank you very much.
When it comes to the disproportionate pollution emitted from motorcycles, that's unfortunate but they are simply low-value targets for emissions control. That doesn't mean stop riding. That line of thinking leads to the same conclusions the most extreme Greenies have been lead to, which is to direct your whole lifestyle to preventing every possible mg of pollution! But what it means to normal people is that we acknowledge the harm of motorcycles emissions and factor it into our weighing of the pros/cons of motorcycle ownership, just like any informed decision we make every day.
Then if emissions controls are ever applied to motorcycles, it means don't complain. Just re-evaluate the pros/cons considering the new factors (cost, performance) and make your decision again.