Kesha's song 'Tik Tok' is one of the catchiest pop hits of the past two decades. It's also very irritating, with juvenile lyrics and a repetitive chorus. We apologize if we've put it into your head by mentioning it! Many people just don't like Kesha's music, and therefore also dislike Kesha. Given the level of autotune in her songs, the accusation that she can't sing is also thrown at her regularly, with the general perception being that she lacks talent, and that her music is vacuous. Also, she spends thousands of dollars each month on glitter, which is just obnoxious.
Whether or not you like her music is a personal choice, but you can't fault her for her commitment to the causes she believes in. Kesha has spoken up in favor of animal rights and LGBT causes in the past, going so far as obtaining a license to perform commitment ceremonies for gay couples. She's also a prominent figure in the #MeToo movement, having called out several figures within the music industry.