I think some of this has to do with habit.
When the 30 sec scan option came out I didn't like it but decided to give it a try, now I like it better than the 30 sec skip option. In fact I know tend to move shows from my Series 3 units to my Premiere because of the 30 sec scan.
In any event I am glad we have choices: various fast forward speeds, 30 sec skip, 30 sec scan, various rewind speeds, and 10 sec skip back are all good.
R.I.P. - 04/04 - Dish 510
09/05 - Humax T-800
R.I.P. - 08/06 - TiVo
05/08 - TiVo HD
06/08 - Panasonic 50PZ800U 50" Plazma!!
03/10 - Series 3
11/10 - Premiere
09/13 - Roamio
12/15 - Bolt