Comment by KyleJune

You could make a similar argument about selling on Amazon. They have rules that you must obey if you want to sell products on their marketplace. If they were not allowed to moderate the content and curate it, then the amazon marketplace would be less appealing to customers and sellers.

Twitter should be able to moderate and curate it's content to protect their brand image. If they don't challenge lies on their platform and remove toxic content, Twitter will become less attractive platform for both individuals and advertisers.