They have some very well trained and skilled fighters. Both local, and some come from outside with previous combat experience in Iraq, or Chechnya, or some nations that offer the type of training once available in the Afghan camps (before they became prime air targets.)
They also have a lot of green volunteers with limited skill who take a rifle and use it to take pot shots at the military. They have little skill but a lot of dislike for the occupying non-Muslim force. If they don't die early on they will get better. Don't underestimate the enemy.
In many ways the noted lack of skill is because of the size of the opposition. The majority of the fighters are random volunteers. If you took random volunteers from the US and had them taking shots at say an occupying force of Chinese, they would probably not be that much better on average.
The Taliban has had some serious victories in the region in the last couple years. So much so that the strategy was revised. Many rural outposts abandoned, and the focus shifting to control of major population centers.
You can call it a tactical repositioning or something else, but it was a retreat from high risk areas that offered minimal gains. Coalition forces are just attacking some of those places again this year.
They also engage coalition forces from well beyond typical ranges of an iron sighted rifle. Engaging in a firefight with much better equipped coalition forces is a quick way to lose a lot of men. Even if they begin to gain the upper hand artillery or air power can be brought in against them.
Instead they rely on asymmetrical warfare. Using booby traps and ambushes. When attacked directly the only smart thing for an under equipped insurgent to do facing the full military might of the world is retreat. Let the advancing soldiers blow themselves up on various traps, and then wait them out. They can only occupy so much area at a time, and when they leave new traps will be placed and the insurgents can move right back in. Only to retreat once more if attacked.
If they actually engage coalition forces it plays right into coalition hands. They take heavy losses for minimal gains facing the most powerful military forces in the world. Exactly what coalition forces want. Instead they want to use attrition, slowly taking dozens of coalition lives with booby traps, mines, roadside bombs, and the occasional ambush on vulnerable targets.
So those taking pot shots are by definition the least methodical, least trained in how to win the fight against coalition forces.
They are the least skilled in asymmetrical warfare. As a result they are likely to be some of the least trained in how to shoot as well.
Those who are well trained, and likely can shoot well know that it is not a war they will win shooting small arms at the most powerful military force on the planet.
Coalition forces actually want them to shoot at the Marines when they are sent in, so they can take out the insurgents while they have the forces and firepower massed in the area!
The insurgents that actually do so are those who are less strategic, and often less trained.
would that their aim of those rpg's was as bad.
They are better with RPGs because
the people actually shooting RPGs are typically better skilled, because an RPG attack/ambush and retreat actually is a viable asymmetrical tactic used by a skilled combatant. Unlike pot shots with a rifle from far away using iron sights against forces in heavy body armor.
So many of those using the RPGs actually are moderately skilled forces, unlike the random villager taking pot shots at coalition forces with a rifle.
Anyone who takes shots at coalition forces is labeled as belonging to the insurgency, when often times they don't and are just some civilian (especially in rural tribal areas with hatred for such forces), that decided to shoot at the non-Muslim occupying force.