So, assume only one of ten civilizations take the expanding choice early. That is still not enough to explain the Fermi paradox.
Unrelated rant/argument:
As a civilization we should publicise "anti heroes" as much as heroes. Those who e.g. destroy something beautiful for short sighted political votes.
Not just the politicians which destroyed our space future. Another example is the present political leaders in Iraq which seems to have caused a war just because they wanted to steal more without interruptions. Would they have done that if they knew their children and grand children would be in the news when their private jets land somewhere? ("Blood billionaires land in XXX, all better restaurants take a holiday. Sorry honest rich people".)
Edit: About the Fermi paradox -- the simplest answer ought to be that there are ET probes somewhere in the solar system and probably with lots of sensors floating around. The scary part is that they don't talk to us; that implies they are studying us and will clean the local infestation out before it spreads from the solar system.
Edit 2: The full argument (I didn't see it in the article?) is that there almost certainly will be lots of civilizations in the galaxy. We have no idea if we are among the first ten or among the second thousand. So statistics say we should probably be in the middle -- there are lots before we existed, we just can't detect them.