From the beginning of the announcement of ICARUS, the New Frontiers expansion was always going to be paid for. In fact, Supporters Edition customer have already purchased the New Frontiers expansion and the Dangerous Horizons expansion. So it is actually the opposite, if we gave away the New Frontiers expansion not only would we not be able to afford that, but we would be doing a great disservice (and need to refund) all those customers who purchased it.
What we did do, was make an entire mini-expansion called "Styx", which we gave away for free to all customers who had purchased the game in it's first year.
Additionally, a free major update is coming soon as part of our regular updates (which we have done 90 of so far), that brings even more content, for free, to all parts of the game including the base game.
I understand that you are upset over the discount and/or the price of the expansion - but please note that making up details about New Frontiers ...