There are worthless skills, but not that many. As Hoss pointed out, the experience tables change the way people are skilling. Currently, it's blow through lvls 1-25, start grouping, oh shit i'm already rank 14, better start training.
I would like to see some kind of benefit of skilling as you level. For example, at level 15, it would take 50% less "time" or insert word <here> of whatever the hell makes a skill go from Awful to Bad, or from Bad to V.Poor than it would take at Level 30. So Barb sharpen for example. At level 15, it would take 10 sharpens to make the skill go from awful to bad, but if you waited till level 30, it would take 20 sharpens to move the skill the same amount. That would incentivize people to skill as they level up instead of waiting till the bitter end which then makes the system appear so awful and grindy when in reality, it doesn't have to be that way.
Obviously, some skills need to be looked at and changed. I fortunately play a healer, so I can say that the skilling up process of Weapon, Turn, Bandage, Brew, Scribe, Meditate appear to be reasonable at this point.