This question can be answered if we look back in our history. Religions always claim that the judgment is upon us regardless of the times. If we take as an example the Judeo Christian religion the Judgment day(s) are upon us since its creation and yet we are still here. Every day new "signs" appear, but always have been proven to be nothing more than people finding what their seeking regardless of the truth. The same can be said for non religious ideologies and beliefs. The "Doomsayer" profession has always been a powerful and, at times, a profitable one.
Generally speaking, people always feel as things are going to hell since we are faced with so many challenges and we end up losing ourselves in our everyday problems and struggles rather than seeing the big picture. Specially today that we leave in an outrage culture were things are taken out of context and hyperbole runs deep within our news media and mentality we get the feeling that things are going to hell when in reality they are getting better. Granted not in every way and not always as fast as we would like them to, but still getting better.
Its no wonder how these ideas primarily comes from the "first world" since we have forgotten how far we come in such a short amount of time and we don't appreciate the luxuries we enjoy that barely a century ago were, and still are in many parts of the world, only thought of as utopia both technologically and socially. We truly leave in the least violent times the world has ever experienced. I will be the first one to admit we still have a long way to go since there are parts of the world were wars still rages daily, basic human rights don't exist and people suffer, but we most certainly aren't going to shit.
Of course there are other factors as well, but the main point is that its in our nature to always want something more from our lives which is both a blessing and a curse. This is what forces us to progress and achieve new things in all areas of our lives but also what makes us unhappy with what we already have.
P.S. English is only my second language so preemptive apology for any grammatical and spelling mistakes xD