The big issue with paywalls for news content isn't the barrier to primary consumption. If people value your stuff, it's reasonable to expect them to pay.
The killer is in propagation of your content. A paying subscriber can't effectively forward your content to non-paying consumers.
Because of this your information will lose to information that can be propagated freely in the competition for the scarce resource of attention spans.
Perhaps a paywalled-content provider could design a special "share this" mechanism that would allow information to be shared (temporarily?) more freely.
Perhaps this would be less of a "paywall" and more of a "paytrap". Hmmm. Is anyone already doing this?