If applied wrong, they can be. But the combination can be helpful.
Charitable skepticism leads you to asking questions about the content. If I say that coffee drinkers live 5 years longer on average, you can ask what in the coffee makes it happen, who did the study, how the study was conducted, etc, etc.
Rather than just saying the whole study is bullshit and dismissing it out of hand. That's more of a contrarian form of skepticism. And it's less useful in learning something.
For instance, if you ask those questions, some of the answers might lead you to something that is useful or interesting. Maybe something in the coffee binds to some receptor that enables blah blah blah (I'm making all of this up for the sake of example, mostly because I'm drinking coffee, so don't actually look for any of this information. It doesn't exist). Or maybe it is all hokum, which is good, because you don't like coffee anyway.
