That's the line I often hear from my friends and families. Do you have any recommendations what to say to disprove Atlantis' existence? Book suggestions maybe?
And question related to post title, really, why those people spend a lot of their time and money to prove existence of Atlantis?? Most of them are not historians. Who gave them the money?
I'm having a hard time wrapping my head around the term "various research."
To your second point, people pay money to hear about Atlantis because it's a fascinating story. And it was possible (while never plausible), once upon a time, to imagine a lost age of high technology.
However, modern science has ruled out such a romantic possibility. We have a number of methods for examining the past that go far beyond the machete-and-shovel expeditions of days gone by. We have satellite imagery and detailed sonar maps of the ocean floor. We have an array of reliable dating mechanisms, and we have ice core samples going back over 400,000 years.
If there had been a previous industrial age, there would be telltale signs everywhere; tree rings marked with soot, huge spikes in CO2 or other industrial pollutants in ice-core samples, hints of past domestication in the DNA of readily domesticated animals, layers of curious isotopes from nuclear accidents or incidents. There was just a sliver of sunlight for the idea of Atlantis 100 years ago. Today, it's definitively an impossibility.
If your purpose is to debunk Atlantis, you can point out that it was not mentioned first by an ancient historian, or by a quasi-religious poet, but by a philosopher who was fond of extended allegory (Plato) in an extremely speculative philosophical dialogue("Timeus"). People hear that some ancient guy said something and they seem to assume it is "myth" and might be based on fact, filtered through oral tradition. On the contrary, context matters.