There's a massive difference between buying something on amazon and "I want my ideas permanently inscribed for others to see in the future, even after I die"

That's seeking legacy, even if it doesn't happen, regardless of if it's benevolent or not. 

That's seeking to protect "your" ideas from vanishing. Seeking to protect "your" ideas from being deleted by the state. 

That's materialistic. It shouldn't matter one way or the other if the ideas are stored immutably, or persist, or not, to an actual anti-materialist.