Another option / the "traditional WSJ paywall sidestep" is to google the headline (copy and paste it from the paywalled article, e.g.) and then visit it from the google results.
If you believe as I do that paywall'd articles do not belong on a news aggregator, the Flag option is at your disposal.
I agree with you. Unfortunately dang disagrees and has explicitly threatened removing the ability to flag from those who choose to flag stories for this reason: https://news.ycombinator.com/item?id=9717601
If you really hate paywalls, the only real solution is to find a different online community.