Firstly, they don't just focus on trading. The mantra that has been used ever since the first game is "Trade Fight Build Think" and those elements are of equal importance. The storyline missions are very much fighting orientated. And as for not coming anywhere close to scope of the Elite series ... in X3TC, there are over 300 sectors to explore, how many systems did you fly to in Elite or Frontier or First Encounters? Yes there may have been thousands or even millions ... but how many did you actually visit? I'd wager it was nowhere near 300. It's been nearly 4 years now, and I still have things in X3TC still not accomplished. It didn't take me 4 years to finish First Encounters.
Secondly, The games are not just popular in Germany, but actually have a following in several countries including America and Australia. The forum has sections for other languages (something I note Frontier have yet to embrace).
And lastly, I will defend Egosoft on here as much as I will defend Frontier on the Egosoft forum, but where as I may be the only fan of X3TC on here, there are actually several fans of Elite on the Egosoft forum.