If it was terror related, the issue becomes of path to extremism, which is what needs to be extinguished. And access to assault weapons. If workplace related violence, it becomes more of an issue of mental health and access to assault weapons.
OK, but is there anything about either of those which we know more about by looking at these guys than we do without them? We were aware beforehand that both of these things need to be addressed, so the particular brand of crazy which motivated Mass Shooting #352 as opposed to those which motivated #186 and #247 is kind of moot when discussing the larger issues.
You mean its moot when a person wishes to fit their facts into a different narrative. One can choose many different definitions and aggregations to prove some pet point about violence, including but not limited to: "all shootings everywhere", "all assaults by weapons", and "all incidents of violence". Each of these are valid categories, and each serve someone's narrative, but that does not make them relevant.
So one begins with honesty, to unsort the manipulation by noting that the numbers you quoted have its origins in a crowd-sourcing website, not official statistics. Then one further notes that that this website defines a count (of four) in a mass shooting (fatal or otherwise) by anyone (police or suspects) of anyone (victim, suspect, police), in any setting, as a benchmark.
But what is the point of doing so? For example, what is useful about counting the death of three bank robbers and a policemen in a crime scene as a "mass shooting", to be lumped into the Roseburg and Planned Parenthood shooting spree of innocents?
It is ONLY useful to confuse, conflate, and gin up the statistics to frighten the public.
On the other hand, you could choose to use the Congressional Research Service's study:
Defining Public Mass Shooting
Policy makers may confront numerous questions about shootings such as the December 2012
incident at Sandy Hook Elementary School in Newtown, CT, that claimed 27 lives (not including
the shooter). Foremost, what are the parameters of this threat? How should it be defined?
There is no broadly agreed-to, specific conceptualization of this issue, so this report uses its own
definition for public mass shootings. These are incidents occurring in relatively public places,
involving four or more deaths—not including the shooter(s)—and gunmen who select victims
somewhat indiscriminately. The violence in these cases is not a means to an end—the gunmen do
not pursue criminal profit or kill in the name of terrorist ideologies, for example.
One Measure of the Death Toll Exacted by Public Mass Shootings. Applying this understanding
of the issue, the Congressional Research Service (CRS) has identified 78 public mass shootings
that have occurred in the United States since 1983. ... According to CRS estimates, over the last three decades public mass shootings have claimed 547 lives and led to an additional 476 injured victims. Significantly, while tragic and
shocking, public mass shootings account for few of the murders or non-negligent homicides
related to firearms that occur annually in the United States.
http://fas.org/sgp/crs/misc/R43004.pdf
In other words, on average we are speaking of 2.5 events per year, with 30.4 people as victims of shooting (fatal and non-fatal).
(And, then one can incrementally add the handful of formally defined terrorist related events, which are even fewer on average).