no, it's because he lacks power and pace. same for fabregas. if we're going to have a CAM, i want it to be someone like prime kaka or rooney, someone with the ability to carry the ball, punish any openings left by defenders, play his teammates in, and curl or power shots into goal like a striker.
for me, fabregas and wilshere should both be CMs only. late runs into the box are fine, but that's very different from giving someone a free role and minimal defensive duties.