Mining income can't get screwed because miners will simply charge more for txn inclusion in their blocks. Either that or all miners will quit, in which case there will certainly be no abundance of block space. Again, self-adjusting.
OK, fair point.
Even with infinite block space, miners can still charge for the service of including transactions.
Take a snapshot of "waiting transactions", and let's say there's 100s of fresh, 'normal' transactions priced from (just pulling numbers out of the air) 0.000001BTC to 0.2BTC.
On top of that let's say there's 5000 'free' transactions on the waiting list. For simplicity, let's say that special transactions with some kind of secondary fee are already covered in the normal group.
Desired situation:A group of the largest miners continuously work hard to keep Bitcoin stable with some central banking theory. They set and continuously adjust minimum fees. This affects the flow rate of transactions in the BTC ecosystem. If there's a price shock -- some major sell-off or buy-up, or some other currency crashes, the idea is that they can always react to dampen that shock. After all, they're
rich in Bitcoin so the incentive is strong.
Bad situation caused by overly abundant block space:A relatively small miner (e.g.: <1%) decides to play by a different set of rules. E.g.: when they get blocks, they accept ALL transactions. This has a disproportionate effect on price and inflation (many people figure "for the
normal fee I'd rather use XYZ-coin because it's cheaper, but because free transactions get through within 2 days anyway, I've got some extra business to do!") So basically you get a small miner potentially ruining, or even sabotaging the hard work that the large miners put in to stabilise.
So you get a sort-of "two speed economy". The large responsible miners only have control over fast ~<1 day phenomena like flash crashes and such-like. However, the slow trends are completely out of control with small miners having disproportionately
more influence. OTOH maybe it's not such a bad thing. Thoughts?