That could be, but the Fermi Paradox is built on a number of assumptions that are severely out of date. Fermi originally outlined his puzzle around 1950 or so. Physics, and our understanding of the fine-tuning of the universe, has made monumental leaps since then, each which exponentially alter the paradigm he was operating in. Even Stephen Hawking's famous book, A Brief History of Time, assumed that all we needed for an Earth-like planet was a solar system similar to ours (which is no common feat to start out with). That was only 1988. Since then the requirements for an Earth-like planet we now know must be present have exploded, both in number requirements and in the probabilities of each requirement that sink the odds ever lower.
Put simply, a planet capable of supporting advanced life like Earth shouldn't exist. Anywhere. The factors that need to be present completely overwhelm the counter-assumptions based on the vastness of space and the potential number of life-sustaining planets it could hold. The Starship Enterprise roamed around the galaxy, visiting and stumbling upon "M-Class" planets (meaning, like Earth) as if the Milky Way was sneezing those things out with regularity. In the real world, they're going to be incomprehensibly less probable, if they exist at all. I say "incomprehensibly" because the probabilities involve numbers so large that they don't mean anything to the human mind. If I said one thing had a 1 in 10120 chance in occurring.....that wouldn't mean anything to any of us. If we then said there's 50 of those things with similar odds (there's way more than 50), and they all have to hit the incomprehensible odds, it means even less.
What amuses me is how science popularizers will regularly gloss over this stuff in pop-level settings. Interviews, articles, books aimed at laymen, etc. Catch them in scientific journals, speaking at conferences with their peers, or academic books, etc., and when pressed, their tune changes to a more honest look at the long odds.
Fermi asks, "Where is everybody?" My personal Bayesian analysis says "They probably ain't there." I don't know that for certain. Neither do I have any first-hand research, obviously. Just the work and opinions of people who study this stuff.
That said, if "they" are out there--or will be out there at some point in the future--there is another explanation that seems to be overlooked in the usual conversations. From what I've seen, the assumption is always that there must be older, more advanced civilizations than ours, so we wonder why they haven't come to see us. They never seem to consider the possibility that we are the oldest, first civilization (or one of them), and so it's going to be the rest of the universe waiting on us to go visit them, assuming a comparable rate of progress in technology across worlds. I find that as plausible as any of the other solutions to the paradox commonly proposed. Perhaps even somewhat likely, since despite the fact that there are stars much older than our own, given the necessity of a bunch of finely-tuned factors I mentioned above, then it could be that if there are other civilizations (or there are going to be others), there won't be nearly so many of them as the vastness of space suggests, and perhaps our planet was the first, despite the fact our sun is younger than many others. Even if one doesn't consider that the likeliest explanation, it should be on the table with the others.
Catsby's favorite explanation, while I don't consider it the most likely, I worry has a ring of truth to it.
