There is an ongoing narrative that we only refer to Muslims who engage in violence as "terrorists" while white people (as if there aren't white Muslims) who commit acts of violence get called "lone gunmen" or get dismissed as mentally ill.
So, I'll start off by saying that this narrative is wrong and I will tell you why it's wrong; but, I will throw you a bone and say that I have observed some truth to it. Only, I'm guessing that tiny bit of truth doesn't have the motivating factors behind it that you're expecting.
The first layer of this is simple. The word "terrorist" doesn't simply refer to somebody who has created terror. Terrorists are specifically people who use violence as a tactic to intimidate people into ideological compliance.
There's a clear and obvious difference between the Charlie Hebdo shooters and the Texas Bell Tower shooter. The Charlie Hebdo shooters were driven to their actions by a fundamentalist interpretation of Islam which prohibits the depiction of Muhammad and definitely prohibits making fun of him. So, they killed twelve people; and, because we all know why they did it and most of you are cowards, they won. The Texas Bell Tower shooter, on the other hand, was motivated by a brain tumor that drove him nuts.
See the distinction? See why one is referred to as an act of terrorism and the other isn't?
The sad reality is that Islam is going through a period now that is like the 1930s Catholic Church on steroids. When it takes two hands to count the number of terror groups associated with the religion, you're gonna have a lot of acts of terrorism to point to. The Garissa College attack wasn't a mass shooting, it was a terror attack. The shootings of Coptic Christians in Egypt have all been terror attacks. Do you know what Boko Haram means? It means "book unclean."
That said, here's where some of you are partly right. I think a lot of media outlets jumped on the Pulse shooter to call him a terrorist and I'm not convinced of that. He seemed to me like somebody who was having serious mental and emotional issues and confusion over his own sexuality who snapped. If the Pulse shooting was motivated by terrorism, it's hard to see what he was trying to scare us into or out of doing.
Where a lot of you may also be partly right has actually come up recently with the Buffalo shooting and the attempted assassination of Brett Kavanaugh. The media haven't been using the word "terrorist" often in either of those cases and they've barely reported on the assassination attempt; but, both of the people who committed or attempted to commit those acts of violence had clear motives to influence politics through violence and intimidation.
That said, monsters like Dylan Roof are correctly called "terrorists" pretty quickly and regularly despite very clearly not being Muslim.
So, why the narrative and why is this happening? Well, first of all, in this country, attacks that fall under the definition of "terrorism" are pretty freaking rare. Even in Europe, they're pretty freaking rare. Sometimes the media do do their due diligence and wait to look into the motivations of these monsters before deciding to report them as acts of terrorism. Yes, sometimes the media do too quickly assume that when a shooter is Muslim that he or she (usually he) was politically or religiously motivated - I'm not denying that that happens.
Still, what's with the lack of the use of the word to describe the terrorist in Buffalo or the Christchurch shooter? I'm gonna go out on a limb and say that I think the media are avoiding the word because it doesn't fit the narrative. Those people were radical, racist, leftists and most of us have bought into the idea that all of the violent, racist assholes are on the right. We almost brush it under the rug that a clearly politically motivated leftist tried to murder a bunch of Republican members of government a few years ago. We associate possession of guns and use of guns with the right. The truly mind-blowing thing about the attempted Kavanaugh assassination was the would-be shooter was actually motivated to kill Kavanaugh with a gun because he thought Kavanaugh was too friendly to the 2nd Amendment.
Should we refer to The Lord's Resistance Army as a terror groups more often? Yeah. They're just not in the news as often as Boko Haram. Should the media be more careful about throwing the word "terrorist" around when Muslims do something bad? Yes. Is it true that there are biases showing in the media? Yes. Is it true that we only refer to Muslims as "terrorists" out of some sort of bigotry? Maybe some people do; but, generally, no, that's not true.