I honestly think there is credibility to the view that they are worried that making the game too difficult will scare away the casual market. Look at how they have trivialised almost all penalties; hull repairs, wear and tear, fuel costs, insurance... all have been removed as aspects which slow player 'progress', or heavily mitigated in the case of insurance loans.
Ramping up AI difficulty, even with a lowered low end (as SJA proposed), could potentially alienate bad players. Suddenly they don't feel like the uber awesome skilled space commander in their A grade whatever... they're getting their backsides kicked by npc, dying in RES and CZ, failing assassination missions, missing PP grind goals. The crying on the forum would have been intense. At management level FD are not concerned with producing a fun, challenging or interesting game. Their primary concern is customer retention and sales of future expansions. Perhaps whoever calls the financial shots has decreed that the game should remain a nice easy grind, because that's what the marketing people say will sell.
