It's not to snub you, it's more to keep the game, and how we play it, in line with what it should be.
A guild is not the be all and end all, an assassin, for example, can be a perfectly acceptable Hunter, if that's what you want him to be. Your merchant too, sure, they won't be the greatest hunters in the known, but you chose to play them that way.
As you gain Karma, and access to more restricted Guilds, the skills and abilities of these Guilds become less widely known. This is, in part, to keep the IC mystery around these guilds powers alive, and in part, to allow you to discover them for yourself.
Although if you read a guilds description, you can usually get an idea of what they're capable of, and will become capable of.
A ranger possesses two primary abilities: to aptly find their way even in storm or darkness, and to stalk and kill prey (for food). Because of the emphasis on these two things, rangers are often greatly sought after as companions in the desert.
Ranger skills involve hunting persons or animals, exceptional powers of observation, a strong aptitude for archery, and some moderate skill with weapons and strategic retreat. Exceptional rangers are able to move silently and remain unseen in the wilderness, detect sounds from far away, work with poisons, and parry enemy blows. Rangers are also often able to rescue friends from deadly situations, bandage serious wounds, and have a well-known rapport with animals, and can ride beasts of burden from the beginning.
While apparently an astonishing array of abilities, rangers are far poorer at combat than warriors, and their skills with poisons and healing powers are actually quite modest.
Rangers are usually the second easiest persons to employ, next to warriors. Any traveller would be a fool to neglect to take a ranger along as a guide, and good rangers can make large sums of money in this profession. In addition, rangers are excellent scouts and spies, able to eavesdrop without being noticed. If nothing else, rangers are superior hunters and can typically feed themselves in such places as the Grey Forest (q.v.), and can bring back skins of animals to sell
So, from reading this, we can pretty much clearly tell that Rangers get two key skills. Direction Sense, the ability to find ones way in a storm or darkness, and Hunt, the ability to track animals/people (not all hunting is the beastie kind!)
We can also see that they're more capable from the offset with a bow than other guilds, and have a small boost to Flee, and is obviously an exploration/combat orientated guild.
I've bolded the most relevant part here.
Exceptional Rangers.....this pretty much means, with enough time played, and focus in training (don't forget to RP it!) That a ranger may one day, be able to work with poison, this is what's called a branched skill. Bear in mind, however, it takes a long time, and most usually never manage it.
If you read each guild's description, you can pretty much guess their skillset without much difficulty. The Higher the Karma requirement, the more vauge and less information given. This is because, in Zalanthas, your average Joe wouldn't know too much about what abilities that sinister gicker has, he could, for all you know, be able to kill with a look, and turn beautiful flowers into raging kryl.
Hope this helps!