Not at all, a few people pay to make it available as a service to others because they want it to exist. It's like this website - there are no (traditional) ads and most of us have paid nothing to use it. A small expenditure creates a good community for technical discussion that the hosts value existing and for being able to occasionally promote their ventures on.

Were the hypothetical "paywalls everywhere" scenario to play out, sites would quickly consolidate their subscriptions. So a subscription to something like Engadget would get you access to a wide swath of sites, making the paywall a lot more palatable overall. This would be the inevitable outcome because it would be the most natural way for sites to compete with other sites.