The problem with UFO-logy in general is that it largely relies on the "I want to believe" factor, leaning almost exclusively on eyewitness accounts and hypnosis to access "repressed memories" - these are by and large the least reliable forms of evidence to the point where science just flats out rejects them. The human mind is extremely good at seeing what it wants to see - a product of our evolution which has served us well for the most part, allowing us to see useful patterns where they don't actually exist, but it can also get in the way of determining the truth. This inherent unreliability of human perception is exactly why science has built in verification methods that UFO claims never seem to be able to pass through.
I'm not saying ET hasn't visited us, but there is no conclusive, empirical evidence of it. Let's assume, for the moment, that the whole UFO thing is and always has been in our minds and there's nothing to this "phenomenon". Now imagine you're the government that knows this - you can't win here; if you stay silent, people who want to believe will accuse you of being a part of conspiracy to cover up the truth. If you open your mouth to say "it's nothing, the Roswell crash was actually something called project Mogul, here's the information", people who want to believe will - you guessed it - still say you're covering it up. You might even conclude that when people see something unidentified in the sky, it can be kind of useful for them to think it's aliens rather than your new, top secret stealth airplane being test flown out of Nevada
In light of that, the behavior of world governments regarding UFO's is exactly what I'd expect it to be if there was nothing to the story. Doesn't prove they're not here, either, but to me keeping an open mind means a healthy dose of skepticism as well. Without that to anchor us in reality we as humans have a tendency to float away where our dreams and desires take us - which can be a comfortable fantasy, but a fantasy nonetheless.
My hopes are a bit more grounded - I don't expect humanity to make contact with an alien civilization while I'm alive, but I do hope we can confirm the existence of alien life on places like Europa before I kick the bucket. Knowing that I can go to the grave safe in my assumption that the universe never makes one of anything, and somewhere out there is some intelligent being asking the same question we are; am I alone?