Asceticism can be based when directed and utilized wisely, however this right here-
>This world is nothing
This kind of thinking and teaching is precisely why evil is winning. Because so called holy men abandon this world to evil and think themselves righteous

Asceticism should be practiced to rid oneself of addiction and weakness, and for the attainment of true power. Not for abandoning the world, but to serve the world and through it the one who created it

Practicing asceticism to hide in a cave somewhere is weakness disguised in the most arrogant and vain mask of them all- a "holy man"