The same thing can be said another devs Airbus. It is currently v1.x with another update (possibly the last) due around the same time that they will be releasing the more advanced Airbus v2. Obviously the changes made to v2 were enough for the devs to decide it would be a different product to the first one, and so will need to be bought by anyone wanting it. So if I want v2, I'm going to have to buy it.

Then there's another devs 747 v1.5. It is not a free upgrade. Once again, the changes are enough to justify them selling it as a separate product, not giving it as a free upgrade. Once again, if I want this one too, I'll have to buy it.

The same thing happened with my buying AU YMML v1. Free upgrades to v1.5. Then I had t buy AU YMML v2.

Like it or not, we are going to have to live with devs decisions to do it that way. Or we just stop buying add-ons from that dev.

So as you can see. It's not just Captain Sim doing it. Other devs are doing it too.