I basically tend to differ, especially with the part about Mannheim. Why?
Let's break it down a bit.
Hockey, as much as I hate to admit it, is one of the marginal sports in Germany that basically has its core of fans and such, but doesn't qualify for a broader audience due to a) lack of media coverage and b) a pathetic league.
We all know that hockey's fairly expensive due to the protection, so a lot of potentially interested kids are turned away by that, too, which results in even less junior players even checking out the sport. We're on the same boat here, so far.
BUT: the actual junior teams in Germany are, quite frankly, a joke. Players who do have talent are being wasted in junior leagues that are neither professional, nor skillful. If anyone ever has the chance, he bails out to North America - and for a reason.
Most of the DEL teams -and Mannheim is included in this list IMHO- don't give jack **** about their own junior players and barely play them, if at all. Instead, they try to lure some wannabe with stone hands to Germany, who might potentially get a double citizenship due to a German Shepherd sleeping in their houses. I've seen many young players come and go -some undeniably gifted with potentially NHL-level talent- and not getting a chance to play in the German Elite League due to the tendency of going with the more reliable player in a more-or-less proven veteran player from NA.
I wish I could go into more detail, but I'm short on time right now due to exams, but I'll definitely get back to this sometime next week and point out the 10 major flaws of our youth development.