I think a couple of points are in order here. First, the "SIM Pilot" you attack so harshly is actually making a valid argument. When a primary task (flying or driving) involves safety, it is reckless and stupid to get so deeply involved in a secondary task (using a laptop/texting) that one is no longer attentive to the primary task.
Second, I think there are two fallacies in your reasoning in condemning him for articulating his opinion. First, as an 18 year-old C172 pilot, your frame of reference is probably more like his than the 10,000 hour ATP, yet you imply your opinion is "more" valid. Also, can you apply your "you can't judge unless you are one" theory universally to your life? No opinion on your medical care because you aren't a doctor? No opinion on the Police because you aren't a sworn officer? What about politics? Can political opinions only be held by politicians?
These forums (like any hangar discussion) are a place to discuss things, including reckless mistakes, in order that we all may make better decisions in the future. If someone has an opinion that is based on incorrect data, we can certainly point out the flaw in the data, but that's not the case here, is it?
So whether it's a computer, a Cessna, or a real aircraft, let's assume we can all have (and share) an opinion on whether or not it's appropriate for a pilot to forget to fly an airplane for 78 minutes.