Why are internal capital letters retained in titles of Web sites in MLA style?
When special typography is strongly associated with a brand, we retain it (e.g., SoundCloud, YouTube). The Chicago Manual of Style supports this practice, advising, “[N]ames that begin with a capital letter and include additional capitals in the middle of the word should be left unchanged” (“Brand Names”).
“Brand Names or Trademarks with an Initial Lowercase Letter.” The Chicago Manual of Style, 17th ed., sec. 8.154, U of Chicago P, 2017, www.chicagomanualofstyle.org/book/ed17/part2/ch08/psec154.html.
Read more about capitalization in titles.