This is ultimately arbitrary restriction, as most can't tell if it is modal consciousness behind the response or CGPT; that is, why on earth would you not just ban the people who contribute nothing but CGPT-tier responses too?
You are confused. The distributed ledger described in whitepaper is valuable when you need to form a consensus about past events under dispute (or which could possible be disputed). Also the ponzi-space of cryptocurrency / blockchain is clearly valuable since you can generate 1000% moons in there for joke coins, it's valued by real money and you can earn real money by trading them.