From the link in the OP:
FBI director: Mateen claimed loyalty to Islamist groups that are opposed to each other
Orlando gunman Omar Mateen told a 911 dispatcher he was attacking an LGBT nightclub on behalf of the leader of the Islamic State, but he also expressed solidarity with the 2013 Boston Marathon bombers and an American suicide bomber in Syria who was not affiliated with Islamic State, FBI's Director James Comey said Monday.
Comey said Mateen's statements added "confusion" about his inspiration for the attack, because Mateen had expressed loyalty to Islamist groups and figures that are opposed to each other.
While working as a courthouse guard in 2013, Mateen made "inflammatory and contradictory" statements to co-workers about having relatives in Al Qaeda, the radical Sunni terrorist group, Comey said. Mateen also claimed to be a member of Hezbollah, Lebanon's Shiite militia, and his remarks drew an 11-month FBI investigation, Comey said. Both groups oppose Islamic State.
He sounds like a wannabe. A very confused young man.
Which means the reason he claimed to be inspired by ISIS was for name recognition only. And the reason ISIS took responsibility for the attack was also for name recognition.
The fact is, his ex-wife said to police investigators that he was not a very religious person. However, he was a very abusive person who repeatedly beat her when supper was not on time, the dishes were not done on time, or for any number of a myriad of reasons.
This shooter was clearly unhinged and wanted to have his 15 minutes of fame. That's what he got, 15 minutes of fame, and although his heinous act will not be forgotten, people will forget the name when asked who did it. They will just say "It was a crazy person".
On another note, I just got back from a memorial to the victims that was held at a nearby Jewish temple over on Braeswood Ave here in Houston. There were Jews there, naturally, but there were also Protestants, Catholics, Muslims, a Hindu couple, and some Baha'i's there. It was a huge coming together of many different faiths, denouncing the attack, and denouncing hate and violence in general. I generally do not cry.... ever.... but this event did bring tears to my eyes. I am not ashamed. I wept.
My take on violence in general is that, in a nation of 300 million people, there are going to be a few who commit acts like this. It can't be helped. It's going to happen, due to the diversity of peoples' mentalities. All we as a people can do is come together and show that, whatever religion we happen to be, whatever color, or whatever nationality, these freaks do not represent us, whoever we are.