loyalty programs – Delta rollover status – better to not cross threshold?

I’m trying to understand the Delta SkyMiles Rollover policy.

It seems like it would be better to not get status in certain situations.

Delta has tiers at 25, 50, 75, and 125k miles.

If I know I’ll fly 70,000 miles next year, then I think I’m incentivized to not fly too much this year.

For example, if I fly 49,000 miles this year, then I earn Tier 1 at 25k, and have 24k roll over. When I fly 70k next year, I reach their Tier 3 (75k) status.

On the other hand, if I fly 51,000 miles this year, then I earn Tier 2 at 50k, and have 1k roll over. When I fly 70k next year, I do not reach Tier 3 (75k) status.

Am I missing something about how the rollover works? This seems like a strange incentive structure, especially given the big step from 75k to 125k (most other airlines have their top tier at 100k).