By themselves, paywalls are the very definition of "fair": you offer what you think is a valuable service and would like to be paid for it. That's fair. You're free to ask, I'm free to not read your stuff if I don't want to pay.

What makes linking to paywalls unacceptable is that links are not marked with a "paywall" tag of some sort. So it ends up being bait and switch and a waste of time.

Regarding subscriptions: I'm just not going to separately subscribe to three dozen news sources I regularly read, I'm sorry.