I've been doing these dailies every day, and the fates always take between 1-4 hours to appear, even if I am clearing out other fates in the zone. More common fates can appear several times over before the fate you need appears once. This is despite the dev team allegedly increasing the spawn rate for specific fates on a couple of occassions. In the time it takes your fate to appear which rewards just 10 seals, elite marks of higher value spawn across the world many times, so yes I agree it's not quite right.