Hunting for traits in the wild sounds disturbingly like New Content, while being able to buy our way out of playing through parts of the game that we don’t care for seems like a sound compromise.
I find this an enormously wise decision, both for players and the developer.
On the player side, part of the draw of GW2 was “play how you like,” meaning visit whatever zones and repeat whatever events you like, WVW to level 80 if you like, and get your exotic equipment from the open world, dungeons, crafting, WvW, or jumping puzzles. I don’t know how everyone felt about it in GW1, but I don’t think the GW2 crowd would be entirely happy with being required to hit specific dungeons or bosses to get traits. I don’t think the hardcore WvW crowd will be entirely happy with diverting gold from rams to trait books; maybe they will (soon/someday?) allow those to be bought with Badges of Honor or currencies other than cash.
I stepped away from Reus due to its unlocks, and I have yet to get back to it. To unlock iron, which seems like a pretty basic resource, you need to make a fairly prosperous town with no animals. Recall that Reus has animals, plants, and minerals, so you are giving up a third of the game for this attempt, and many plants and minerals depend on animals for bonuses. I made a short game, set up a few towns with no animals on the map so I had a few chances, and proceeded to have almost every special project appear with animal-related bonuses or requirements. I am reasonably certain that I could tough it out, finish that map, and finish my unlock, but doing this just raises the specter of future unlocks that will require similar annoyances. Annoyance is not what I want in my gaming time.
As a developer: gold sink, ho! Players can buy gems and sell them for gold, so new ways to spend large quantities of gold prop up the price of gems and make purchases more appealing. Players are paying to skip the game? Normally, that would sound like a design issue, but $$$.