Except there is no evidence that, as you stated, Matteen committed the shooting because he hated gay people. Investigators concluded that he did not target Pulse specifically because it was a gay bar. He chose it at random because it was an easy target.It has nothing to do with whether I feel bad or not. I'm just smart enough to realize that people don't always speak the truth.
Terrorists always make themselves out to be principled, honorable warriors. They don't usually say, "I am killing these gay people because I hate gay people." Or "I'm robbing this armored truck because I need the money." It's not a noble path forward. And thus, terrorists have all sorts of excuses. The Brinks armed robbery that landed Kathy Boudin in prison for life was supposedly about the ongoing struggle against imperialism. It wasn't. They needed cash.
Similarly, if you read about the Red Army Faction in Germany in the 1970s, you would see that they committed acts of violence in retribution for all sorts of different perceived crimes. In the end, though, they were just violent people. If you think they wouldn't have taken hostages in Sweden if only Holger Meins had not died in prison, I've got a bridge to sell you. [incidentally, the character of Hans Gruber was based on the Baader-Meinhof Red Army Faction, if that tells you anything about the perception in Europe of the RAF's motivations]
During his wife's trial in March 2018, her defense revealed in a motion that Mateen had Googled "downtown Orlando nightclubs" and, after passing Disney Springs, traveled between Pulse and the Eve Orlando Nightclub before choosing to target Pulse. Cell phone records indicate that the final selection of the Pulse appears to have been made based on the lack of security – not because it was a gay club. Trial witnesses said the decision to target Pulse was made at the last minute and the defense's motion argued that this "strongly suggests that the attack on Pulse was not a result of a prior plan to attack a gay nightclub."
Once again, the attack was an Islamist terrorist attack carried out by a radicalized Islamist terrorist. These are facts, not opinion, and they are not up for debate.