I think the point you seemed to have missed is that building a fertilizer bomb is not as simple as obtaining a gun in many places in the US. There are no specific fertilizer bomb stores. There are no fertilizer bomb “shows”. They cannot be reused, you would have to build a new one every time…unlike a gun. They are illegal everywhere because they are bombs, and and every time you make a new one, you risk blowing yourself up first…which is a great feature!
Running a truck into a crowd, I mean sure, but I doubt you’d take out, say, 20 (just going off of what the current number of dead is in Maine), or 60 (Las Vegas) people. The Boston bombing “only” killed 3 people, so yeah sure I guess I’d prefer a relatively few people to take the time to make one and, assuming they didn’t fuck up, sure, I guess some innocent people could die here and there. It would suck, but I like trying to minimize easily preventable deaths. People escape from prison, too, but most don’t, and so we don’t just throw our hands up and say “oh well, guess we won’t investigate” every time that happens.
And I guess you could run a truck into an elementary school classroom somehow and manage to mow down 19 kids, but I really doubt it. I don’t have anything to compare that to, unlike…well yeah there’s been a lot of those in schools to look at over the past 20 or so years, so pick one.