Change your sexual orientation, get 10% off your flight

Jon, my virtual landlord, sent along this link, which shows how carefully companies need to position their discount offers.

Alaska Airlines and Horizon Air decided to offer a 10% discount to gay travellers who booked their flights through a particular page on their website (at the time this was reported, the page was titled "Gay Travel", but it had changed to "New York City on Sale" soon afterwards.

I have no problem at all with airlines or other businesses offering discounts to individuals or groups, but this is an example of how not to do it. How much does offering the discount to people based on their sexual orientation (or declared sexual orientation, which isn't quite the same thing) differ from offering a discount based on the colour of their skin? Would that not cause serious objections from government and private organizations? Could Alaska and Horizon have managed to find a way to increase their business that didn't run the risk of alienating the a significant number of their existing customer base?