Ender was suited to be a brilliant military commander precisely because he hated killing so much. A more bloodthirsty commander would have fallen for certain traps, committed certain errors of judgment that Ender was immune to. The nuance here is that Ender's strategic advantage came from a tremendous empathy with his adversary.
In the end, Ender had to be fooled into destroying the Buggers precisely because of this empathy. He never would have been able to commit a genocide if he thought it was actually a genocide, but he could do it in the context of a video game.
And, for what it's worth, the childhood bullying delivered by Ender's brother was also a function of Ender's love for his brother. We see very soon that Ender is capable of tremendous violence, but he tolerates mistreatment from Peter because he loves him so much.
It is this victimhood which endears Ender to any reader who has felt victimized, by showing that in some cases there is great physical and moral power beneath the surface.
The author of this strange hit piece is clearly trying to rile up various reactive political groups against Card. Sure, card is a Mormon and appears somewhat socially conservative in his personal beliefs. He is clearly not homophobic and became defensive when he sensed that the author was trying to broach the subject which had probably caused him much pain.
Sure some people believe that anyone who doesn't advocate same sex marriage qualifies as homophobic... The author of the Salon piece clearly thinks that state recognition of same sex marriage is hugely important.
I'd argue that through his books Card has done far more good (by enlightening people about important moral issues) than any harm caused by his traditional view (restricting the word "marriage" but not the state sanctioned bond between two people).
The remarks about Card yapping and flirting suggest a very immature person wrote the article. Clearly at a certain point Card was trying to be polite and let the interview finish without incident... something that was framed as "shutting down"... Bizarre stuff.