In addition to all the other reasons cited so far, there’s also the fascination with a much younger planet, with a greater degree of vulcanism, full of lush primeval forests (cyclads and ferns, before the evolution of modern deciduous trees), and whose oceans teemed with more primitive versions of fish and sharks. And with no people or even mammals, which makes for some interesting daydreams about how long one person or a small community could last in such an environment. Speaking for myself, my fascination with dinosaurs was never just about the dinosaurs. It was really the gestalt of their era: dinos plus volcanoes plus weird exotic forests and swamps, minus all the people, cities, “friendly” critters like dogs & cats, and our own beasties.
Adding to the lure of the otherwordly is a modern combination of escapism and nostalgia, fueled by the growing realization, steadily ascendant since the Age of Colonization, that civilization has not only mapped out and settled the planet and conquered the flora-and-fauna part of nature, but has also hunted, clear-cut, mined, torched, farmed, paved, subdivisioned, polluted, and now heated the hell out of it. The story of evolution thus plays out like a Biblical fable: primitive creatures begetting evermore complex species, until man came along and dominated creation (as no other species ever could), but to the point of ruin. The dinosaurs, however, managed to dominate their Garden of Eden without despoiling it. They existed within the state of nature, of course, without any civilization or even higher consciousness, but that doesn’t prevent us from feeling a tenuous identification (even if only in kindergarten) with T. Rex and its ilk.
Another thing: since we didn’t coexist with dinosaurs, it goes without saying that they, alone of all the great beasts of our own time, escaped the predation and domination by humanity, and retain a certain dignity and mystique as a result. They were never hunted or herded, domesticated or fenced off in nature preserves, put on display in zoos, genetically typed, and mated. On the contrary; the dinosaurs were mankind’s greatest terrestrial rival, in the sense that their domination basically precluded our development and was cut short only by the advent of the asteroid. I don’t know if the evolutionary narrative I learned as a kid holds up today, but what I learned was that the dinosaurs were so well established that mammals were unable to evolve beyond the level of tiny shrew or rat-like critters (and perhaps the dolphins in the seas). Anything larger couldn’t survive against such superior predation. Today, our earth is stripped of the mysteries and perils of antiquity, and the only possible lifeforms threatening our survival as a species, aside from microbial epidemics, are the distant spectre of planetary invasion by a species of technologically-superior extraterrestrials – another subject of ongoing fascination in its own right, and for much the same reason.