Delete your *.wsj.com cookies, use a referrer control addon and set it to google.com for wsj.com and enjoy clicking HN links and not see the content block.
I don't love it, but I don't have a problem with it, mostly because I have no idea what other route they could take.
Ad-supported is something Buzzfeed can make viable, but it means tailoring both the substance and the form of their content to optimize for that. Doesn't work for WaPo.
I'm fine with the WSJ doing this. Businesses are free to monetize their content as they see fit.
I don't like that a link to a WSJ paygate page gets this amount of votes on Hacker News, when there are numerous free links available for the same information.
If anything, I'm saying "don't vote for paygate links" to whoever clicked to upvote on the OP link.
They have to be very careful -- Google's guidelines are very strict about content that they index. If you display different content to a user than the content that Google has indexed, that will cause Google to drop the page from their index, and may affect the overall quality rating for your site in Google's index.
Nobody really wants to cross them here; if you want your content indexed and displayed in search results, you have to show the full content to users inbound from search result pages.