And that advice is to listen and learn and be gracious for any feedback from anyone, especially those who have achieved success in the very field in which you are seeking similar success. And, very importantly, if you seek feedback, expect to get both good and bad and embrace BOTH. The good is great to hear but the bad is what is going to make you a stronger writer or filmmaker if you listen and learn from it.
Though in your face, I am very sympathetic to Josh's sentiments. I too am asked to read tons of scripts and it's my job to do so and I enjoy it. But sometimes, after having taken my time away from my own projects to read a script and provide some insights, I get the same pat response Olson's friend gave him or sometimes even NO response from the writer. Like Olson, it stings.
I have to agree that it's really hard to read someone's script and know that it isn't very good and then have to think about how to kindly be honest and supportive. It's not easy and it takes time to write those emails, even if they sound generic to the screenwriter. You don't want to offend someone who has spent a long time writing a script but you also don't want to just lie and say it's great because how is that helping him or her achieve success?
Unfortunately, you can't please everyone. I just hope people listen to Olson and realize that though he has achieved success, he is still human and deserves to be handled with respect. I'm sure he is reacting mainly to the fact that this writer was pissed and dismissive of Olson's efforts to provide honest feedback. In the end, we all could stand to be better and let's be grateful someone cares enough to tell us so.