By the other rand, communication have reached a scale that we could not imagine or reproduce without the internet.
Although I agree with you that most of times to discuss online will be a pain in the ass due to the very point the author have made, several important issues are being discussed right now which we wouldn't be doing had internet not existed.
For instance, atheism and religion have never been so debated and atheism is growing in the younger tear of the population.
Eventually debates will get more mature and we will maybe discover that internet is the ultimate tool for that. Again, nothing is perfect.