I asked you a direct question. Why not provide a direct answer? Which era, specifically?
Keep in mind, we've had terrorism in this country for pretty much the whole of the modern era -- going right back to the age of the "bomb throwing anarchists."
And we're not just talking little acts like this one, that managed not to kill anyone. Not all that long ago we had about 3,000 killed in a single terrorist attack, and not long before that 168 were killed in the Oklahoma City attack, and not long before that 241 of our countrymen were killed in the Beruit bombing, etc. Terrorism with explosives had been a fact of modern life ever since there have been widely available explosives.
Now, of course, we can imagine some make-believe era when there were no pressure cooker bombs, but there also weren't much higher murder rates than today, nor mass lynchings of "uppity" minorities, nor near-genocide of Native Americans, nor slavery, etc. But if we're going to move away from our imaginations and look just to the real world, is this really a bleak era, as you suggested? I don't think so -- not in context. I think all in all, it's the best time to be alive.
Would it be better to be in the early 1990s or early 1980s, with murder rates so high that it would be like having
six 9/11-magnitude terrorist attacks happening
every single year? I don't think so. Compared to that, having an occasional pressure cooker bomb go off is a walk in the park.