I'm not convinced that bigger operations necessarily are more short term oriented. They are however more profit driven. A solo-miner will probably have much lower stakes than a big operation renting several warehouses. Also the solo-miners are much more heterogeneous as they don't have the resources to do all the last tricks to optimize their earnings. Merged mining, MEV, things like that are probably out of scope for them while big operations invent products and play politics.

Now solo miners do usually mine with pools that do all these shenanigans and I don't see how to shift the incentives away from pools but as long as the switching costs are low, pools might not be a big problem anyway. Miners that want to do the right thing will switch if some pool(s) turn out to be evil.