Let me rephrase that. (Where is the "Edit comment" button?)
>> Is there any proof or even indication ... would not have been conceived without patent protection?
> Yes, there is, if you consider the aspects of reduction to practice, publication and dissemination. Prior to the late 1970s, method patents via software were difficult to obtain, and special-purpose hardware was very expensive in time and money. This significantly impeded the publication and dissemination of new ideas, methods, and algorithms in software during those years.
Does this mean that the drawers of European universities are full of beautiful algorithms left unpublished because they cannot be patented? It is hard to believe.