Ignoring all initial bonuses, you'll be able to get 70K MQM per year without flying a single mile, assuming you can spend $160K annually on your Delta credit cards as follows:
Spend $50K on a Delta Plat Personal, Earn 20K MQM
Spend $50K on a Delta Plat Business, Earn 20K MQM
Spend $60K on a Delta Reserve Business, Earn 30K MQM
Totals: $160K in spending nets 70K MQM annually. 5K short of top-level status for Delta.
* In the first year, you can get 75K to 85K MQM (just gift any extra MQMs above 75K to a friend) by also collecting the various signup bonuses, depending upon which ones you qualify for.
ALSO OF NOTE:
You can do something similar to achieve Gold US status each year. You need to be able to qualify for 3 Juniper US cards and 2 BOA US cards, but if you can pull it off and spend $25K on each, annually, you'll get 10K EQMs from each card for a total of 50K EQMs on $125K spending.
Anyone able to charge $160K+$125K=$285K per year can virtually get Delta PM and USAir GP without flying
