When you complain about pirates demanding more money from your small miner, you forget that they don't charge per your cargo hold. They charge per your ability to generate money over time.
And your mentality is what's wrong with this whole "miners should not be pirated. Go pirate ore shippers". NO. Miners should not be excluded from being prey just because they are smaller fish to catch. What next? Are we going to demand that no capital ships may fire on small pirates, because capital ships should go do something else? Come on.
Pirates are not here to harass you ooRPly. They are here to give some danger inRP. And if these changes are introduced, while miners would be most affected, same would go for pirates who caught something in mining field. Reinforcements could catch them just offguard as pirates caught miners.