They are not purely a publishing company because they are also a relgion, to that extent you are correct. However, they relied on publishing and the revenue it provided more than any other religion I can think of. They even called their members “publishers”! Pioneers were premier literature distrIbutors who obtained literature at discounted rates. The whole purpose and drive of the organisation was to print and distribute more and more literature in more and more branches.
The message was incredibly important too, you are correct about that. And it’s certainly a testimony to the loyalty of their members that the organisation has been able to continue to function for the best part of quarter of a century after their primary source of revenue came to a juddering halt. But the lack of revenue from publishing has clearly taken its toll. First came the paperbacks to replace hardbacks, then the calendars stopped, and the bound volumes, and so on and so on, until the yearbooks were dropped and the magazines decimated.
For over a century Watchtower boasted that they never take collections and their members are not tithed - they didn’t need to, they had the luxury of their publishing empire as their source of income. Now that has dried up they are relying purely on donations, and despite all the cutbacks and sale of assets, it’s still not enough to dig them out of the financial hole they are in.