VISA and religion aside, difficulty optimizes mining for an ideal market condition. What desirable mining environment should block markets maximize?

A)Potential for inclusion of any and all transactions always
B)Immediate space for 40x current volume with a blind increase and another eventual hard limit
C)Inclusion of most non-spam* transactions most of the time, based on necessity
D)A scarcity magnifying limit that caps transaction volume and velocity starting soon

Most users don't want D. Non-generating nodes don't want A or probably B. Generating nodes want the most profitable [valuable] thing possible. Adversaries want A or D

*Most would agree that creating volume to intentionally fill blocks and slow the network qualifies as "spam"