Blue Mage is a masterpiece of game design.

[Akor]

Nonsense. Shout is a necessary tool for finding groups from Eureka to BLU, Hunts are announced via Shout too, and to a lesser extent, Yell and Say. To hide any of these means to risk gimping your experience of the game and missing vital communication.
The only person who's fault it is for spoiling things, is the person spoiling it.

If u dont want to get spoild your going search for ppl who dont want to get spoild. You either create PF for this or u hope ppl who dont want to get spoiled dint hide shout or chat in general. You just cant blame ppl who shout out whats the next mob they need to kill. You cant enforce ppl to stop spoiling it for you.

Like Billy sayd, other ppl want to know what comes next.