This contradicts statements from other community members that claim they like the danger of being able to get ganked at any moment. It's one of the reason they play a full PvP game. Only trading by fast travel would be a big case of cognitive dissonance and a voluntary limitation on their own enjoyment. In which case you can blame the player, not the game/feature.
I believe what you said is nothing but pessimistic assumption, however. I don't feel such pessimism is in place when we have one of the friendliest and most sincere communities of any MMO.
I consider myself one of such players. However this is not how it would work for me.
I will not go out of my way to make it riskier for myself. It is quite the opposite.
Even though the risk of the game is what makes the game exciting for me , I am always trying to reduce it any way I can.
So, If there was fast travel then I would surely use it when I needed too.
Even if doing so would lead to a duller game that is less thrilling.
But we are getting away from the more important reason of no fast travel.
And that is the distribution of regional resources.
It is by design that resources are spread out. This should make demand high for products that are out of a region.
Then players can risk transporting in demand items to these places for profit.
So, even if I was not to use the quick travel. Someone else would. And the results to the economy would be the same.