Didn't cbloader and hero labs pull from the online ddi database?
CBLoader loads XML files that were originally provided by WOTC. You could get the data to incorporate newer things from the Compendium, but you can also just write your own XML files. There were tons of them floating around too. People have done a LOT of mods. Remember, offline CB only worked with 2009 vintage stuff. It didn't dynamically connect to DDI either, it was just sent updates periodically that gave you the newer stuff.
So, if you have CBLoader, and data, you can do without online CB, though people may question the legality of it. Given that WotC told us in the EULA that we could keep using offline CB even if we quit DDI I don't see where anyone that got it legitimately has any reason to feel guilty about still using it, nor about updating its data files with data they can already access from the Compendium (or could when they were last a DDI member, which is the same thing nowadays). Nor is there some reason to believe that adding data to your own CB yourself is unacceptable, AFAICT.
Obviously that only covers a subset of people. I don't actually know much about Hero Lab, other posters can enlighten you on that, but I think there's at least one other tool out there that doesn't rely on DDI, but on community input of material into its database. I could be wrong though. I know there's at least one poster however that did say something about not needing DDI anymore because he had these other tools.
Anyway, I think it sucks that DDI is fading into the twilight, but it doesn't make 4e unplayable. It makes it supported electronically to the same degree as 3e or 5e. It WAS a selling-point of the edition, so its too bad, but we can live with it.
