This kind of resembles JetBlue's FF program, 30 MQS AND $4,000 minimum (15,000 flight points at 3 points per $ spent).
I really don't find the spending thresholds to be an issue, but as a segment qualifier, I spent >$4,000 for 37 MQS. Now, I just wish they'd let us qualify for a higher level on MQD alone, once you exceed some minimum number of MQM/MQS. That'd be awesome!