Some can, some can't for whatever reasons. If nothing else, people are taking information and ideals expressed here with them into their daily lives and sharing them.. could be around the copier at work, waiting for the subway or even while being interviewed by Brit Hume! There is something to be said for that.
We don't get many opportunities from FReeping down here in South Alabama, but we do have the bad habit of discussing politics and religion (when we don't think any yankees are listening!), and I know I've enlightened quite a few people about the Clinton way of thinking. Those people take what they learned with them into the polling booth and hopefully, make wise voting choices. Same thing with the folks who saw the DC FReepers on a daily basis... something had to have sunken in.
Anyway... I definately see your point, just let's remember that there is value even in yaking.