In infinite wisdom stephen voss answered:

Well... That depends on one's point of view.

We are being constantly bombard by the news, fact books, 'experts',
and so on that there are no ETs in our solar system or on/in our
planet. But are these things true or not? If these things aren't true,
is it just an honest mistake or there's something more sinister behind
it?

The reason why alien civilizations may not want to communicate with us...

1) If you watched our signals, you would assume that there is a nominal
world government but that we are currently in a state of civil war
and have been so for the last 60 years.
2) An independent observer would view earth as primitive aggressive warlike xenophobic and politically unstable.

What if they're all of the above and worse than us?

Why do you assert that ET must be morally superior? Does the word
'anthropomorphism' ring any bells?

If I were leading an advanced scouting team for an alien civilization,
I would recommend continued discreet observation of the world in question.

No doubt because of the prime directive.

Also the issue of radio waves is not as simple as it seems.

It seems simple?

It is possible that there is a narrow range of time from
when it becomes possible to use radio waves for that purpose
to when a species becomes sufficently advanced as to no longer
use those frequencies.

Or perhaps, their communications will be via different channels?

Such a period may only be 200 years or less.
In an additional 100 years...the technology for listening to
the old frequencies may disappear.

Then radio astronomy will be at an end.

The Fermi paradox is not really valid for the following reasons.

1) If youre going to realistically maintain long term interstellar
communication youre going to have to develop reliable FTL communication...which we cannot currently detect.

The Fermi paradox is not about "long term interstellar communication."

2) The Fermi paradox is good math but lousy social science.

"Social science" is an oxymoron.

The roman empire mathematically could have colonized all of Asia,Europe and Africa in a period of 1000 years or so...but even beyond the battles. Their supply lines would be overextended.

The Roman empire was not supplied from Rome.

Also the cost
of sending out colonies requires wealth that the satellite colonies
may not have.

The colonies do not send themselves out.

3) Its much easier to colonize 14000 nearby stars within a 100 light years than to send ships all over the galaxy.

Is this not also true for every colony?

4)The population curve suggests as a species becomes more prosperous
they have fewer children. Without huge booming populations, the
ability to have sprawling colonies quickly is reduced.

I'd say that prosperity is more important for sending out colonies
than huge booming populations.

5) expansions of civilizations is not a steady thing, civilizations have
boom periods, decline periods, and some civilizations may just decline
to nothing.

True. But all would not have to prosper, only some of them.

Beyond a certain range civilizations do not spread unless there is some
sort of technological improvemment.

Where do you get this?

One other factor, if they're not there they also won't prosper and
colonize. If they exist they may have no interest in the stars or
ET life. I'd imagine that there are numerous variables.

Rich