If "MiNi" was a sub-set of cheap fares available on every flight, then yes, the more expensive tickets would earn miles. But they've not introduced "MiNi" along those lines - it's only on certain routes from what I gather, and ALL fares are MiNi (unless you buy up to the ones with bags/miles), and therefore the pricing behaves like on any other flight - the fares can go up as departure approaches and/or as the cabin starts to fill. And yeah - it is ridiculous.
Speaking as someone who has only ever qualified on segments, I've got to the stage where I am no longer aiming for requalification.
Think about what you'd miss without your current status. Does it really amount to much?
Once you make the decision to get off their hamster wheel, it's actually quite liberating. And you can usually find better deals on other carriers, anyway!