The trouble with paywalls is, am I going to pay for NYT, WSJ, Boston Globe, MoneyWeek, Newsday, The Onion, etc, all individually? No. I might subscribe to one paper, but that's not how the Internet works. Even then, I never subscribe to the paper. I get it free at work or at the library or in a hotel.
IMO posting paywalled sites to a news aggregator detracts from the experience of using the aggregator for anyone who doesn't subscribe to that paywalled site.
Its established that a low percentage of people are convinced into signing up by a paywall. There for, posting paywalled articles to a news aggregator detracts from the experience of everyone who chooses not to subscribe to that particular site because it robs us of front page real estate that could be held by other non paywalled but interesting stories.
Consider a news aggregator where every link went to a paywalled site, so many disparate sites that you couldn't afford to subscribe to all of them. Would you find the aggregator more or less valuable than one that had freely available information.
Maybe there is a place for paywalls in this world, I just don't think we should be posting links to them here.