Do debilitated planets always give bad results?

Yes debilitated planets always give bad results.

Below in brief I have mentioned, planetwise, the adverse impact of their debilitation.

Sun – It gets debilitated in Libra and makes the native arrogant with low IQ.
Moon – It gets debilitated in Scorpion and makes the native emotionally unstable (weak EQ) and even turn insane.
Mars – It gets debilitated in Cancer and makes the native argumentative and waste all his energy on unproductive issues.
Mercury – It gets debilitated in Pisces and makes the native impulsive and unreliable.
Jupiter – It gets debilitated in Capricorn and makes the native highly manipulative.
Venus – It gets debilitated in Virgo and makes the native remain unhappy.
Saturn – It gets debilitated in Aries and makes the native lazy and unable to have a career or profession.

Rahu and Ketu being shadowy plants, 180 degree apart, always retrograde, hence their debilitation can be determined based on their exact position in the chart with reference to other planets.

If you notice the debilitation of planets gives the native evil habits which if not controlled are life derailing.