Unfortunately, it seems this is an issue that won’t be fixed. Despite it being an issue for many users, talking about it typically just leads to downvotes even if the comment is productive in that it proposes solutions. It would be simple to fix either by allowing users to blacklist paywalled urls or creating an auto-outline bot or something but for whatever reason it doesn’t seem to be worthy of addressing despite the fact that invariably there are people that have issues with it as evidenced by comments like this one in pretty much every paywalled submission.

It’s a shame, really, because it likely prevents a lot of good discussion that would take place if everyone could read the linked content.