I agree, I really think this is a bug and they do intend to give at least one aircraft for standard edition users for heavy cargo, otherwise they would have just had that part locked and saying that you need to purchase it as an addition. I’m sure this will be fixed at one point, as BeeJayHawk mentioned, many aircraft is not included yet in career and the ones we have are also quite buggy. It is also in their interest, as a standard edition user, I am actually inclined to take a higher edition later on to fly more airplanes.
On the other note, I think the majority of people don’t actually care what others do in their career, it’s a single player progression, anyone can decide how they enjoy it. Some people might be complaining and taking it as competitive, which I can not understand, there is no leader board, nor in-game economy that is impacted by this. As for the developers, I think at this point they just can not support modded games as the vanilla has many problems that they want to sort out, mods do make it harder to narrow down the cause of these problems. I really hope they dont want to introduce credit packages for a single player career mode. Paying for new aircraft or handcrafted scenery, or further content, thats all good, but credits and career progression makes zero sense to be monetized.