I think the implication is that "rent seekers gonna seek" is a fact of life, and that "a government that resists rent seeking" is the part of the equation we might be able to control.
> Why should we accept rent seeking as inevitable?
In my mind, a couple big reasons.
One, for the same reason that we accept a lot of awful things like murder as inevitable. Of course we'd rather get rid of these things, but it's unrealistic to think we'll get rid of them completely, so the systems we have in place for dealing with them when they happen will always be very important.
Two, because these things are often in the eye of the beholder. What I see as "rent seeking", you might see as "providing a public good". Most people (on HN at least) think current US copyright law represents a lot of rent seeking by Disney. But most of the same people still support some notion of copyright. There's no clear line where "public good that most people agree with" ends and "rent seeking" begins.