The community consensus is that HN is better with links from sites that have paywalls (NYT, New Yorker, WSJ, The Economist etc are some of the most influential publications in the world, so banning them would diminish HN's relevance and usefulness), as long as there is a known workaround to the paywall. Usually someone will post a workaround in the discussion thread, but https://archive.is/ is usually your best bet.
If it's a "hard paywall" (i.e., no workaround exists), then the submission should not appear on HN.
Post a comment protesting it whenever you see it.
Use a browser extension to disable all the links.