People should grapple with these questions in a sustained, deliberate way, with reference to what's already been said and where arguments are evaluated critically by many eyes. That's what academia is for.
He engaging in philosohpy doesn't necessarily justifies the existence of humanties departments in universities. With spread of internet and MOOCs the first even departments that should cease to exist on state money are the humanities departments.
Humanities are the only departments that should exist on tax money.
It's not there is no value in opinions, there is, it's just that people have come to expect the rewards of knowledge for having opinions. And reality doesn't work that way.
And for anyone who actually cares about this point, there was a well known study of psychological experiment replicability I was alluding to which should be part of the assumed context for anyone discussing such topics. It is also painfully formalistic to attach qualifiers to every statement when that is not the cant of a forum like this. You should know this, but instead you're latching onto a lingusitic formalism as a defense of your point instead of arguing the point head-on.
Sorry humanities people. The science and technology people are way more useful than you and most of them are smarter than you too. There is no intellectual equivalency between the domains despite the perennial protestations of the humanities faculty.
If we lose this, then it will be a sad day imho.
Edit: PG even wrote a post on this http://paulgraham.com/disagree.html