Pews are a blessing for people of all ages.  With children, in a pew, they can sit, have books to look at, color, look at what is happening in front of them, etc.  In a church without pews, a child is stuck in the middle of people, looking at their backs, or knees, or shoes.  
\I think that part of getting people involved in Liturgy -- or Mass -- is to educate them about what goes on, encourage them to participate in prayers and to think about the meaning of those prayers..  I know that in those Ukrainian Catholic congregations where the entire assembly is encouraged to participate in chanting the Liturgy, the response is better.  My daughter mentioned to me the other day that it must be very boring to just stand there and wait for it all to be over.