That's insane. German MR points transfer to most bonus programs at a 5:4 ratio. Meaning I would get 0.8 Avios (for instance) for 1 MR point.
US MR points transfer at a 1:1 ratio, and then sometimes there are bonuses where you can get 1.25 miles for each MR point or so.
In other words, just transfering DE -> US -> Avios instead of DE -> Avios would yield ~1.2 instead of 0.8 miles per MR point, a 50% increase.