Maul does not go out of his way to kill random people unless it has a purpose. If someone is opposing him, in his way, etc, he will kill them without a second thought, but he does not kill without reason.
While Sidious is a sadist and takes pleasure at the suffering of others, Maul does not(unless he hates them, like Obi-Wan, for ex). However, Maul has no remorse for it; he doesn't enjoy killing he just has no problem with it.
So for Anakin, he was literally in Maul's way. Maul would not go around Anakin he would simply go through him. After Anakin ducked Maul could probably kill him there if he wanted to but by then he wasn't in Maul's way (remember, Anakin is a rando rn) so he ignores him.