Are you suggesting that to be a good critical thinker implies being skeptical in any and all matters of the heart?
I would suggest that being a "good critical thinker" implies applying critical analysis to all matters, be they "of the heart" or otherwise.
Have you ever had any experiences in life which were an emotional catharsis?
Irrelevant. Cathartic emotional responses do not require irrational thought, and are not necessrily invalidated by critical thinking. In fact, many of my own cathartic experiences have come as a direct result of applying critical thinking and embracing skepticism.
Why must we always become skeptics by default? If it works, who cares whether or not it is a placebo?
What we "must" do is a matter of personal values. If one values a rational outlook on how the world actually works, then skepticism is a necessity. If this is not a priority, and living in a fantasy-land is acceptable so long as it "works," then skepticism is unnecessary. But make no mistake - without skepticism and critical thinking, universally applied, it is impossible to maintain a rational and reasonable understanding of objective reality. Flights of fancy, including "faith," correspond to reality only through bare chance, and far more often lead to inaccurate conclusions.
Failing to use reasonable skepticism and critical thought results in gullibility, nothing more.