I'd say we should want it. Currently it's installed and enabled by default however you can turn it off. Also it will be appreciated in development mode. It does not make any harm to have it as fallback, that's one of warden cool feature I think.
I see your point that strategies should be isolated. But I just need to check whether it failed previously or not. More readable would be ho have some flag :openid_failed however adding extra flag seems a bit redundant. Maybe just use better naming?

something like

```ruby
use_fallback = (params[:username] || params[:password]).present?
Katello.config.sso.enable && !use_fallback?
```