I had a tablet but I never got the hang of it. Extremely small size was one, not having something to look at was another. Oftentimes the next touch after a quick lift-the-stylus rest break is well away from the previous marking, whereas with pencil art I can get a reasonable level of accuracy that I want (I say reasonable because accuracy itself has been a ***** to me in manual art before).
I'm still too used to the direct feeling of paper (and even then I'm still not good enough in manual art), but I've long come across some shortcomings of manual drawing already and it's pissed me off enough times. Not to mention paper art is nowhere nearly as useful as a model produced in a 3D application, but that's a different topic.
But, on a more related note, Wacom's Cintiq series is seriously expensive... enough to keep it well away from the reach of the casual indie user.
Shoot... but then again there's bound to be enough reasons as to why it costs so much, so no point for me to argue really.