The wiki description of pretty accurate
Kālī (
/ˈkɑːli/;
Sanskrit: काली &
Bengali: কালী; IPA:
[kɑːliː]), also known as
Kālikā (
Sanskrit: कालिका), is the
Hindu goddess associated with empowerment, or
shakti. She is the fierce aspect of the goddess
Durga.
[1] The name of Kali means black one and force of time;
[2] she is therefore called the Goddess of Time, Change, Power, Creation, Preservation and Destruction.
[3] Her earliest appearance is that of a destroyer principally of evil forces. Various
Shakta Hindu cosmologies, as well as
Shākta Tantric beliefs, worship her as the ultimate reality or
Brahman; and recent devotional movements re-imagine Kāli as a benevolent
mother goddess.
[4] She is often portrayed standing or dancing on her husband, the god
Shiva, who lies calm and prostrate beneath her. Worshipped throughout India but particularly South India, Bengal, and Assam, Kali is both geographically and culturally marginal.
The highlighted in red part means some people trying to do black magic end up bringing Kali the bad rep she has in media. Actually her worship is perfectly normal like any other deity.