It's not personal opinion though. Have a read and you start to see there are defining principles to each design style. It's generally easy to see if a hole fits a penal / heroic / strategic mould (as per the fried eggs examples). There is no opinion to that, there is demonstrable analysis and logic to his conclusions.
Now if you like or don't like a certain style, of course that's personal opinion. But you can't say 17 at sawgrass being a penal hole design is "opinion".