Strikes that come from the side (rather than straight on) can often be sneaky. My guess is that it has to do with how fine tuned a person is to their peripheral vision, and whether they can 1, visually see and 2, perceive the sideways motion as a threat. A hook punch is an example of this sideways strike; and when kicking, the roundhouse kick acts in the same way.
The target for a roundhouse kick can be high or low. If your want to be able to execute a kick with height (eg, a kick to the head), you need to work on your hip mobility (that’ll be addressed in another Bando minute). If you want to fight in a tournament, you’ll need to be able to get your kicks approximately waist high. (Many tournaments have rules that forbid kicking “below the belt”.) In self defense, a kick to the thigh or the lower leg can be effective, so even if you can’t kick at someone’s head, roundhouse kicks are still a good tool to have in your arsenal. Today’s Bando minute is about your balance and control.
1. Set up with kicking leg in back 
2. Kick over the top of the chair, keeping shin parallel to ground
3. After clearing the chair, bring foot in front and then to the knee 
4. Step down to the side of the chair. Then reverse the steps!
This is another exercise that takes advantage of a folding chair. Having a physical chair lets you know if you are actually clearing the height you’re aiming for. (And if the chair back is too high, you can use a shorter chair or other item.).
Let me know how this works for you! — Debby