Agreed - software like this doesn't exist in a vacuum of frozen dependencies (at least not until Urbit takes over). Subscription models make sense for stuff that requires updates over time to keep it working. Their stuff is reasonably priced and the product has been really good for years (imo).

I suppose they could do something like JetBrains where you get updates while subscribed, but realistically login breaks for users would be a mess to support and a standalone text editor is a different service.

This move makes sense to me given their market. Those that want to run a vault can use an alternative that's more of a hassle to deal with.