I'm not sure what anyone's point here is. Yes, most mainworlds are in the habitable zone because that makes the most sense. And it is moderately rare that worlds in the habitable zone are severely masked. That happens with certain sizes of stars. It's probably more common now because our understanding of star probabilities is different than in the past, but that's not how Traveller is designed.
The entire economic structure of the game is based around being able to jump to close proximity of the main starport. If you can't reach the main starport from the jump point within a day at merchant speeds (M1 or M2), that world is going to require specialized trading solutions.
One solution is to not put the starport on the main world. Another is to classify the more accessible world as the main world even if it isn't the 'best' world in the system. It's the main world for TRADE purposes. A third is to use some kind of LASH system where large trade ships unload cargo lighters and pick up new cargo lighters outside the jump shadow and continue on without a starport visit.
Another solution is to change the pricing structure of shipping so that you don't have to jump every other week to cover expenses.