The mind-numbingly trivial activity of safely moving goods from goods from port to port without any interesting decisions or consequences is folded into the colony system. That's what they're doing--moving goods in quantities sufficient to profit even through tariffs. In this respect, so-called "legal trade" is insanely profitable.
On the scale of the player character, the game realizes that trade is, for most people, an extremely uninteresting activity compared to combat, and attempts to throw some interesting wrinkles into the mix. Let's face it, playing Han Solo is far more interesting than playing a UPS driver.
It's not a question of *playstyle*--the playstyle of a trade focused character is mechanically supported. In the end, "legal" vs "illegal" is simply quibbling over a cosmetic distinction. The game is more ambitious in its trade mechanics than other similar games, requiring more interesting decisions to be made. It could dress these up any way it wanted.
As for roleplaying, even big budget sandbox games have practical limits to the number of RP considerations they can support. Not every conceivable fantasy will be supported. I'm sure that someone will Mod out tariffs, thereby reducing the challenge and complexity of the trade system, for people who find it cosmetically unappealing.