According to the world, Moorakh is such person who has less worldly intelligence and Siyana is such person who is intelligent worldly-wise. According to Gurbani, Gursikhs are Moorakhs as far as this worldly definition of Moorakh is concerned because worldly intelligence is about gathering Maya whereas Gurmat is about shedding Maya. Maya is not just money but anything that takes us away from Vaheguru.
A Gursikh needs only as much Maya as much is needed to survive but worldly intelligence preaches to ensure that one gathers as much Maya as possible. If man is given opportunity, he will reserve every single penny for himself alone, he will store every grain in the world for himself, he will bring every woman in the world to his harem; basically he will take everything he can get his hands on.
On the other hand, a Gursikh looks not at the worldly possessions. For a Gursikh gold and mud are same, lust is unthinkable, and money is not required beyond meeting basic requirements to survive in the contemporary world.
So when, Gursikhs who are imbued in the divine colours of Naam, forgo worldly wealth or make choices that result in them losing worldly opportunities of rising, they are severely chided by their worldly relatives and when the Gursikh remains adamant in not pursuing the worldly aspirations, the world starts calling him a Moorakh.
On the other hand, Gurmat preaches such persons, who go after false wealth (worldly wealth) and shed the true wealth (of Naam), as Moorakhs. Such Moorakhs, who in fact are real Moorakhs, who are enchanted by the spell of Maya and never even in their dreams think of gathering the wealth of Naam, are truly incorrigible i.e. are beyond reform. In the following Shabad, Siri Guru jee talks of such incorrigible Moorakhs who are beyond reform:
ਮ: ੧ ਸਲੋਕੁ ॥
ਮਛੀ ਤਾਰੂ ਕਿਆ ਕਰੇ ਪੰਖੀ ਕਿਆ ਆਕਾਸੁ ॥
ਪਥਰ ਪਾਲਾ ਕਿਆ ਕਰੇ ਖੁਸਰੇ ਕਿਆ ਘਰ ਵਾਸੁ ॥
ਕੁਤੇ ਚੰਦਨੁ ਲਾਈਐ ਭੀ ਸੋ ਕੁਤੀ ਧਾਤੁ ॥
ਬੋਲਾ ਜੇ ਸਮਝਾਈਐ ਪੜੀਅਹਿ ਸਿੰਮ੍ਰਿਤਿ ਪਾਠ ॥
ਅੰਧਾ ਚਾਨਣਿ ਰਖੀਐ ਦੀਵੇ ਬਲਹਿ ਪਚਾਸ ॥
ਚਉਣੇ ਸੁਇਨਾ ਪਾਈਐ ਚੁਣਿ ਚੁਣਿ ਖਾਵੈ ਘਾਸੁ ॥
ਲੋਹਾ ਮਾਰਣਿ ਪਾਈਐ ਢਹੈ ਨ ਹੋਇ ਕਪਾਸ ॥
ਨਾਨਕ ਮੂਰਖ ਏਹਿ ਗੁਣ ਬੋਲੇ ਸਦਾ ਵਿਣਾਸੁ ॥੧॥
1. Ocean is known to have pearls and jewels but what does fish have to do with ocean (it goes after meat for food only); what does the bird have to do with the greatness of sky, it flies but is only on look for food.
2. What can cold do to a stone (can't soften it) and what does an eunuch have to do with householder's life?
3. Even if you do massage of dog with Chandan paste, it still stays a dog and goes after bitches only.
4. How can you preach to a deaf through religious books like Simrities and Vedas (he can't hear them).
5. What difference does it make if you light 50 lamps around a blind person (he's still in darkness).
6. If you place gold near cow herd, it still chooses to grass only (does not know about gold).
7. By adding flux to iron (and heating it) you may melt it but it does become soft like cotton.
8. Same way, an incorrigible Moorakh( is beyond reform and) always speaks such words that bring destruction.
But what can Moorakhs do too? They don't have the fortune written on their foreheads to engage in Bhagti. For this reason they can never understand Gurmat and always stay anti Gurmat. It is for such Moorakhs that Guru Sahib has instructed us to not debate with on points of Gurmat - ਮੂਰਖੈ ਨਾਲਿ ਨ ਲੁਝੀਐ ॥
The word Moorakh has been used in Gurbani with both positive and negative connotations. When Guru Sahib calls Himself "Moorakh" it is said either in the meaning of Nimrata (humility) or innocence or in such meanings as being devoid of worldly Mayadhari intelligence. When this word is used for an Bemukh or Manmukh person, then it means such person who is devoid of Gurmat i.e. one who does not engage in Naam Simran.
Gurbani is Agam Agaadh Bodh.