There's a bit more to it than that. My tops would be two points.
First, we're memetically infectuous. Plant a new idea here, and someone will run with it, most likely in some direction you never wished for. Many of our memetic infections are downright dangerous, lethal, destructive, etc. Contact might well be considered irresponsible, no matter how well intended.
Second, there's the thing I mentioned about our reverse-engineering technology. They might accidentally give us more capability than they wanted to. Not that we'd be any threat to them, but we've been sitting here for however long with the Doomsday Clock close to midnight. Give us something new that can be weaponized, (We've been able to turn just about everything into a weapon, perhaps the most resistant invention was the "death ray", the laser - it's had so darned many peaceful uses and has been very hard to make into aweapon.) and we will do so. Perhaps that weapon might be what tips the scale, ticks the clock, or whatever metaphor you like.

First, it doesn't explain Fermi's Paradox, it merely adds another term to it. In all of those various probabilities, apparently there is something like a 10% chance of not getting taken out by a gamma burst in half-a-billion years. I would also expect the odds to get better as a given galaxy "settles down", generating fewer big, hot stars and more smaller, calmer ones. Some neighborhoods are probably rougher too. I wouldn't wait around to settle Trantor, near the center of our galaxy.

Second, I wouldn't consider intergalactic contact in any serious way - the distances are bad enough for interstellar, do we really want to add a few more orders of magnitude?

Third, our presence establishes our galaxy as one of the more benign ones. There is at least one neighborhood that has been sufficiently peaceful for the last half-billion hears. Last I knew, there were no supernova candidates close enough to cause that kind of trouble any time soon, either.

Fourth, I'll focus on your word "silliness", which I think you meant as an understatement. There is conceivably a chance that we are under observation, and rank as "too silly" for any contact. The Earth has had an oxygen atmosphere for the last half-billion years, and we're on the verge of being able to detect other such atmospheres on other worlds such as Kepler has found. It's not a bad assumption that any civilization capable of interstellar travel is also better at planetary surveys than us. If they're there and within a few thousand light-years, they know something worth seeing is probably here.

At this point in physics we're stuck at the Standard Model. We have many theories that move beyond, but no facts to select among them, and many of the experiments would be incredibly expensive. But let's say one day we saw a "warp signature", it's quite possible that we could immediately discard half of those theories. (By "warp signature" I really mean physical evidence of truly advanced technology.) IF there were here watching us, and seeing our "silliness" as well as the scientific acumen of some, they would be especially careful that we see no such evidence.

Cars made of memory metals will spoil that one, too. Heat the wreckage to the right temperature, and have it spring back into a car.

Hmmmm.... I wonder how far The Culture is from Roddenberry's ideals? In some ways, The Culture seems to me to be a far more realistic post-Singularity type of civilization than the Federation. The trappings are far more fantastic, (GSVs, anyone?) but TOS tended to underestimate many things. As one example, the communicators were basically phones, and other than communicating with an orbiting starship instead of a local tower, they only do a fraction of what today's smartphones do.

Plus even The Culture gets to have explosions. I'm currently re-reading "Surface States". The first time I read it, I particularly liked one Ship giving a fairly complex blow-by-blow account of a space battle that was only something like 15 microseconds long.

I was rather amused by the titles of the Tanya Harding / Nancy Kerrigan newsgroups, though to be honest I don't remember the titles any more and never read them. I just remember ".whack.whack.whack" being the tail end of one.

I actually did follow and post to technical newsgroups.

So is your desk a standing-only desk, or one of those that moves up and down? My wife has been looking at one of the latter.

However in Europe you've been warned. In the US we walked (or sat?) way too far down this path before discovering how bad it is. Now that we all know better, you can change your path before getting where we are.

OTOH, my wife are generally stupified looking at twenty-somethings smoking. Our parents didn't know better, and in fact during WWII the Army included cigarettes with meal rations. During our generation (I'm a later Boomer.) we sort-of knew better, but the cigarette companies didn't actually admit they were lying until well into my adulthood. For this generation there's no doubt about how bad cigarettes are, but if anything smoking seems to be on the rise.

I wonder if Hari Seldon would have said that masses of people are stupid, as well as predictable.