There's a flaw in your reasoning. No need for it to be a "shoddy port".
Except time, money, and patience.
There is no reason people cannot put the effort in to make a good port and thereby gain additional income from the product.
Your missing the part where they've looked at the situation and said "We don't have the skills to do this as well as it should be done. The money isn't worth hiring out or the hit we'd take for doing it poorly. Let's stick with what we do well."
Just cause you wish to play it on the PC doesn't mean it would be a good idea for them to try and make it.
-ZacWilliam, Sure if they threw enough time and money at it they could probably make a decent port but they know better than us whether that's a good proposition for them.