IMHO, jeans are a blessing and a curse for pocket carry...
Jeans have some real positives for pocket carry -- the thick denim resists printing very well and the gun is retained well -- i.e., will never fall out. You can also very easily hang shirts over jeans (not tuck the shirt in) for additional concealment.
HOWEVER, most jeans pockets are pretty tight. Even if the pockets are decent size, the openings are small, making extraction difficult. Gun size plays some part in it, as does you hand size. Sometimes you have to draw the gun with your fingers as opposed to a true firing time grip, which would be ideal.
Pants, hand size and guns vary quite a bit -- but I don't think the pocket holster is the problem.