Interesting, but not very convincing. The argument concerns historical periods when the costs of research were not nearly as high as they are now. As your own source rightly points out:

"the total cost of bringing a new drug to market [is] around $800 million, in year 2000 dollars... [T]his figure suggests a spectacular increase in the cost of innovating. This increase is due, mostly, to the capitalization of the longer and more expensive clinical trials the FDA requires."

It may well be that patents were not always necessary for drug development. It is lazy thinking to conclude from this that they are not necessary now.