I'm wondering whether it is even possible for Bitcoin to enforce a rule that goes against the will of the market. I strongly suspect the answer is "no."
As an example, consider the block size limit. When it was put in place five years ago by Satoshi, it served as an anti-spam measure. It was actually 800x larger than Q* so the vertical line marked Qmax was actually 100 ft off the chart! Since the production quota was to the left of the free-market equilibrium point, it didn't affect the market dynamics. There was no economic pressure to change the limit.
[.....cut....]
If the market wants to be at Q*, but the production quota is forcing it to be at Qmax, what can a group do to continue to enforce the production quota against the will of the market? How can the invisible hand be restrained?
As you state. The block limit was imposed to combat "spam". In fact. I don't agree with the term "spam" since they are still valid transactions but the system cannot cope so they were marginalised to protect the integrity of the system. I expect the limit to be removed once the system has been developed to cope with any number of large or small transactions and see that as the main design goal.
Anyway. The introduction was a hack. A band-aid to sort out properly later. I view it as a temporary technical limitation being exploited by economists in an attempt to monetise the block chain directly. I take a very dim view of that in the same way I take a dim view of those alt-coins that attempt to pay the developers with the protocol. It's like gamblers finding something to bet on after they had their cards, coins and dice taken away. They have found a chink in the system that
allows a market and are now trying to open it up for further exploitation.