From reviewing various movie clips, I tend to notice a 100% kick attack success rate, but a nearly 0% lightsaber attack success rate. Is there a canon explanation for this, or is it simply theatrics? The kicks seem so much slower! Wouldn't legs just get chopped off extremely frequently?
In-Universe some of the kicks are from trained martial artist duelists, Out-of-Universe Inverse Law of Utility and Lethality applies
The kicks you see Darth Maul so graciously use in combat were a carefully developed style, allowing that way for a higher chance of success.
Most species were known to engage in this kind of combat, and a number of sentient species and cultures also developed it into different martial arts proper; just as the various lightsaber combat forms could be applied unarmed, so too could many of these unarmed combat styles be applied with the lightsaber.
Darth Maul and Anoon Bondara were both students of the Teräs Käsi martial art, developed by the Followers of Palawa, who became accomplished lightsaber duelists.
However it could be anticlimatic if lightsaber duels were finished by a quick effective strike; some people speculate that in real life a duel with such a weapon would be indeed very short. It happens in many shows that the deadlier the weapon the less frequently it strikes preventing this, tvtropes name this Inverse Law of Utility and Lethality and Inverse Law of Sharpness and Accuracy.
On the other hand short duels can be indeed awesome and very emotive as demonstrated by Obi-Wan.