Almost everything in the bolded graf is factually false. That is probably why you are surprised.
The reason the "anthrax" letters to Trump officials didn't get much press is because they were not in fact Anthrax or anything else hazardous, which they knew pretty much right away. It did get quite a lot of coverage until that was known, then it dropped off the radar. Which is what one would expect.
The baseball game shooting? That was top story for days and had constant follow-ups and coverage. Not sure why you didn't see it, but it was very much there, big time coverage.
The Rand Paul episodes with his neighbors have been covered on and off for the entire time, but that one is also weird because Rand Paul himself has wanted to keep it quiet. His choice I guess. I honestly don't know anything about comedians saying stuff, probably true, that's kinda what comedians do.
I find no stories from anything other than wild conspiracy sites about any attempts by ISIS (or anyone else) trying to assassinate Trump. Of course all Presidents get threats, the USSS handles it, and we generally hear nothing about it unless something leaks publicly. And people violate motorcades and other security perimeters pretty regularly, again, for all Presidents, so why cover something like that unless they actually make it close to the President?
I mean, that might help explain it, Or the fact that, you know, actual working bombs were sent to like a dozen people from a terrorist. Seems kinda newsy to me.