Nike is pro-homosexual sex, pro-adultery, pro-dog fighting, and pro-bad behavior from athletes in general. They are however, perfectly happy to discriminate against people who are opposed to these things. Like all leftist hypocrites Nike argues from the premise that their worldview is the only one that is legitimate. When they say they will not tolerate discrimination what they really mean is they will not tolerate discrimination against their worldview.
I may soon regret commenting, but it is not discriminatory to reject as a paid spokesperson someone who is at odds with the values of the organization paying said spokesperson.