Dunno about the rest, Furious, but I suspect the reason the LW tends to be tight-knit in most sims is because it tends to be in a minority. Add in the occasional idiot accusations of being "Nazis", then that in organised games there's usually some folks who much prefer flying Allied who have to come fly with the Axis to make up the numbers, and if we share with them anything that we think MIGHT give us an edge, then the Allies will obviously get to know of it and be able to counter it all the faster... (shrugs). We also very often end up fighting superior numbers even when a game isnt planned that way... that tends to weld folks together.
When one looks at the planesets of various flight sims over there years, I personally think there is a justifiable case for saying there has been a degree of bias against Axis-side planes, at least in terms of plane types offered. Actually, it's probably even more true to say that there's been a bias in favour of the US (in regard of variety of planes made available to fly) at the expense of everyone else, in the past. Even the RAF has been treated as a poor relation...
Of course, there are some cogent points as to why this might be the case - most games still dont adequately deal with night flying and night combat, and so types that spent the bulk of their operational career flying at night have tended to get left out (so long, RAF bombers... - and some LW ones). Games in this genre have tended to take fighter combat as their starting point and then tacked everything else on, AND started with something like MA play, which militates against planes that cant survive well in that kind of environment, especially in the days before most sims gave us at least some degree of usable cloud cover. But doing things that way doesnt create a game that mimicks WW2 air combat; it allows people to have simulated aerial fights using simulated WW2 kit, not quite the same thing. It's taken a looong time for the industry to show signs of starting to overcome that bad (but perhaps understandable) start. Sorry, I digress..
My main complaint with WW2 combat flight sim publishers has been the dearth of Axis level-bombers. I look forward to my first online Battle of Britain re-enaction where I can fly a LW level bomber of the period OTHER than a Ju88. Happily, it looks as though AH is progressing and expanding to the point where it can sustain a number of types typical of various parts of the real war that don't survive well in the anarchic madness that is the MA. Fingers crossed, I'll get to fly a Heinkel 111 or - dare I even hope it?! - a Dornier 17 in a BoB game one of these years. Lovely though the Ju88 is, just the chance of a change now and then is good. The Ju87 doesnt cut it because its not a level bomber, and the Ar234 doesnt because it's a late-war jet (although also a thoroughly lovely plane to fly - in simulation in AH, at least!)
I just wish we could muffle the "need for speed" fighter whiners a tad... - but then, us bomber specialists tend to have more patience than some of the fighter types. Just as well, I suppose... (smile...)
Anyway - for what it's worth, there's my tuppence ha'penny on why us Luftwoffles are close-knit.
Esme