You forgot no share dilution in this offtopic tangent. Every stock out there can double their issuance if they want to.
Miners won't because it would devalue their coin.
New buyers might because they can "buy cheap"
Nit: it would also require a hard, not a soft fork.
No, it would be a hard-fork and be rejected by all nodes that weren't explicitly updated to accept it.
Or not, you don't know. Maybe a friend of the board wants to have a controlling stake in the company and that's the reason.