It's a preference about a certain stereotypical aspects of the German military. For one thing, them being the historic loser in the first place, intrigues and invokes interest in a lot of people.
Psychologically, there are two different preferences in people when they assume a certain 'role' to themselves; the first type is the "othodox" type. They pick the historic winners.
If it were a classic fantasy-based role-playing game they'd probably be on the "side of the light". For a certain "job", they'd pick something like the casual and normal 'warrior' or the 'knight' and etc etc.
The opposite preference to that also exists, which is known as "the unorthodox type".. as some people prefer to choose the "side of the darkness". In role-playing games they love choosing the uncommon, weird, and unorthodox type of characters. Its can be viewed as a surge of individualism by denouncing and rejecting the normal conditions.
A classic example is the movie "Star Wars" - while many people are intrigued by the noble of order of the Jedi or the Rebel Alliance, a lot of other people are more interested in the Empire. Those two are opposite extremes - the Empire appeals itself in its uniformity and organization, unlike the Rebel Alliance which is basically a loosely formed rag-tag band of warriors who are living symbols of Bohemian freedom.
As a general rule of thumb, the "orthodox types" set higher values in emotion and freedom, relating to the concept of "Romanticism". On the other hand, the "unorthodox types" stand on the side of reason, self-control, organization and discipline - which can be summarized into the concept of "Modernism"
Ofcourse, this doesn't mean the former is a careless irresponsible person, and the latter is a regular neo-Nazi.
It's just a way how our inner cravings and sub-conscious values, and fascinations, manifests itself in the form of virtual identity. For instance a person could be very reasonable and organized in his normal life, but his subconsciousness may choose to convert, and express itself in the form of the opposite side when an opportunity rises - such as when we create alter-egos in gaems, or root for certain heros or anti-heros while watching a movie. Much the same, a very free and liberal person, might choose to become something very different when he makes up an alter-ego.
So basically, one type of person is a "Dr.Jekyll and Mr.Hyde" sort of being, while the other is "no differences, both inside and out".
And no other type appeals to the unorthodox, than the German side, in these sort of games.
I'm definately the 'unorthodox' type. I hate flying things which many people already fly. I hate making up same type of characters when playing role-playing games. I don't care if my character is weak or sucks balls - as long as its original. As long as its pretty much certain that no-one else develops his game character in that way, I'm satisfied. I'll choose the ugly looking guy, or the fat guy, or the wierd freak type of character when playing games. In martial arts fighting games, I'd choose the character with the most weird/absurd type of fighting style.
And when it comes to AH, I'll usually fly German in the MA. If in the CT I'll play the Axis. If German planes aren't available I'll play with the IJN/IJAAF planes(but not the Niki..), and if both of them aren't available I'd stand on the side of the Soviet planes rather than British or the USAAF/USN.
It's just that something different from the 'mainstream' intrigues me more.
