Although we may tend to look at a hobble skirt as sexy, in my opinion it is far more elegant than sexy, if properly full length. The restriction of gait produces mincing steps, which while very feminine, produce a gliding motion, because the hips do not move much. Look at a Geisha walking, or Morticia in the Addam's Family TV show: she walks very smoothly and level, because there is no other option. Only when she dances do the hips start to move.
A sultry, sexy sashaying walk is produced by a skirt that is very tight at the knees, but looser below, such as a wiggle skirt or mermaid skirt. With the knees restricted, the lower legs are forced to swing around, driven by a rolling of the hips, producing a head-turning wiggle. Yes, she can walk faster, but stairs will be her nemesis - check out Zahia Dehar on Youtube for good examples of that.
Ultimately, though, the lady in the long hobble skirt is more helpless. Check the scene leaving the train in Baltimore in the Funny Girl movie. She can't keep up! (Can you imagine spending all day around town in that dress as she was about to do?).