The comparison is actually quite apt. In fact, Oracle is doing less harm than many apps that switch to a paid model, or get acquired and shut down. Consider that BDB is still licensed under the GPL. It's just the new releases are released under the AGPL. You can still use the GPL version.

When an app switches to a paid model, you aren't left with a choice. So even if you invested time and energy into integrating it into your system, you are sunk. You generally don't have a choice.

And if the app stops being produced (e.g. Sparrow), it can never be improved. At lease the BDB allows people to improve the GPL version if they want.

So really, the issue is only a problem if

* You were already modifying the BDB source * You need the latest version

Considering the people with the problem are already modifying source, it's not as if they can't fork BDB. Sure, the cost for using BDB has now gone up, but that can be compared to adopting the AGPL and the changes needed.