Yes, there are instances where someone managed to book a 25,000 mile domestic roundtrip. Anecdotal evidence aside, this is NOT the issue.

Pick a city pair at Delta.com, then choose a desired travel date for a SkyMiles travel award. That's simple enough. If the award calendar offers up a 25,000 mile low award (not likely!), choose it, and wait for the purchase summary informing you that your low award requires 60,000 miles. There you have it. There's nothing difficult at all about finding a 60,000 mile "low" award on the SkyMiles award calendar.