Yea, 7 lug, and the wheel pattern change up is among ford's many MANY stupid ideas.
In all fairness, GM has had its share of bad ideas, too.
* What's up with running 5 and 6 lug wheels on the same series of 1/2-ton truck? Makes finding wheels a bit of a headache.
* Why are 1/2-ton backing plates so slightly smaller then 3/4-ton ones? Barely different, yet incompatible.
* Why bother with 27-spline tranny-->T-case shafts?
* Why did 3/4-ton trucks get 10-bolt front axles?
These are just square-body annoyances. Other models have their share as well.
* Why did it take so long to finally produce a decent 1/2-ton O/D manual transmission? (They were YEARS behind Ford in this category)
* Why did they think that pump-mounted drivers (6.5TD) were a good idea?
* Why, why, oh why did 14bff axles continue to place the brake drum behind the hub? This was never a good idea, but still it persisted far longer than it should have.
* Yes, they changed their lug spacing, too.

* And countless other things from various models throughout the decades.
Ok, rant off. I obviously prefer GM to other brands out there, but that doesn't mean that they're exempt from stupid ideas. Hindsight is 20/20.