Wikipedia would rather have readers assume that Cook is heterosexual, because being gay is bad.
Here is what Wikipedia doesn't want you to read:
Cook's sexuality is a matter of some speculation. However, as technology reporter Michael del Castillo has noted, "...by all accounts, Cook is a gay man, although he's never talked publicly about his sexual orientation. Gawker in 2001 called Cook the 'most powerful gay man in Silicon Valley' as it quoted 'two well-placed sources' who the site said confirmed the Apple exec's orientation. Out magazine placed Cook on its Power List of the 50 most-powerful LGBT people this year."
On November 3, 2013, Cook published an editorial in the Wall Street Journal in which he advocated for immediate congressional passage of the Employment Non-Discrimination Act, and sent a memorandum to all Apple employees on December 22, 2013, reaffirming Apple's commitment to nondiscrimination on the basis of sexual orientation or gender identity.
 del Castillo, Michael. "Tim Cook's Memo Takes Public Battle for Gay Rights to His Employees." Upstart Business Journal. December 23, 2013. Accessed 2013-12-23. http://upstart.bizjournals.com/entrepreneurs/hot-shots/2013/12/23/tim-cook-memo-mentions-gay-rights.html
 Cook, Tim. "Workplace Equality Is Good for Business." Wall Street Journal. November 3, 2013.