Just to add that the lack of earning isn't A3's fault. Simplistically speaking, the way FFPs work is that when you fly with an airline and put your number into the booking, the airline you fly with will pay your FFP a sum of money for your loyalty in keeping within the Alliance.

Depending on how much profit the FFP wants to retain, they will give you some miles back which they nominally value at less than the money they've received, i.e. FFPs are profit centres.

In the case of Lufthansa Group, the likelihood is that they are not paying Aegean any money (or at least a vastly reduced amount) if you take a flight in a non-earning fare bucket - and therefore there is no margin left for Aegean to give you any miles in return.

Clearly airlines like TAP and Air Canada are more generous, because their Business fares earn at 2x. They do this in the hope that you're more likely to fly with them than LH if earnings are important to you.