After the pilot flying failed to level at 4;000 FT MSL as cleared; his Captain addressed his concerns that a too precipitous descent required when flying the ARVIN STAR into BFL was a contributing factor.

Narrative

We were on the Arvin arrival/ILS 30R into BFL and were at around AMONT and were told to maintain 4;000 FT after two other step downs to 9;000 and 7;000 FT. The arrival lines up straight in to the runway and we were having to (as usual) use a higher than normal descent rate to make it down. For some reason we are brought into BFL much higher than most airports. Descending down to 4;000 FT; we can also see where the ILS glide slope is in relation to us. At 5;000 FT I called out for 1;000 FT to go and after a few moments I studied closely the TCAS for traffic that was pointed out earlier and to try to see any other traffic. I looked up and my First Officer; who was hand flying at this point; was quickly passing through 4;050 FT and I took a moment to register this and then point it out to him that we were cleared down to 4;000 FT. His flight director command bars were also directing him to climb at this point. He slowed down the descent and was able to bring the vertical speed to zero at about 3;650 FT. This is all above the glide slope. About 4 seconds later after we received a clearance for the visual approach and landed uneventfully.The steep descent and airspeed reduction that also had to be accomplished could have been done with the autopilot turned on; but my First Officer felt like hand flying it. My observation with people hand flying who also have flight directors is they don't obey them like an autopilot would. I do myself and if I don't feel like following it I turn it off; but until then I do what they tell me. So the First Officer kept hand flying even after a more reasonable and constant airspeed; but still higher than normal descent rate was achieved. He admitted a false need or fixation to capture the glide slope even though we weren't yet cleared for the approach; probably because we were higher than the glide slope at every stage of the arrival.The straight-in-from-forty-miles-steeper-than-normal-over-the-mountains approach into Bakersfield always has slight ATC variations in it according to local traffic. Personally; if it were up to me I would have a bend in it from the south starting at GMN to allow a less precipitous descent angle and a chance to slow the approach process down a bit to allow for clearer thinking. It certainly would be nice if we could pick up ATIS earlier; too; but there is much interference from Palomar/Carlsbad Tower.