Majjhima Nikaya 152 Indriyabhāvana Sutta In this sutta, the Buddha teaches how different people should approach sense-restraint. Here, the enlightened ones can perceive objects in a different light (positively, negatively or dwelling in equanimity), whereas beginners should be repelled in sense-objects.

My question:  (i) What does "repelled/disgusted" mean literally? 
                         (ii) Isn't everyone capable to perceive the good in the bad and the bad in the good? Why did the Buddha made such a distinction?
(i) What does "repelled/disgusted" mean literally?


The commentary, translated by Bhikkhu Bodhi, says:


  Although the sekha has already entered upon the way to final deliverance, he is still prone to subtle states of liking, aversion, and dull indifference in regard to sense objects. He experiences these, however, as impediments to his progress, and thus becomes repelled, humiliated, and disgusted by them.


The Pali words used are aṭṭīyati harāyati jigucchati.


  (ii) Isn't everyone capable to perceive the good in the bad and the bad in the good? Why did the Buddha made such a distinction?


This is an interesting subject. Based on the abhidhamma it seems some states are to an extent intrinsically "attractive" and others are intrinsically "repulsive". How intrinsic these qualities are, I'm not sure. This sutta seems to affirm that they are intrinsic but an arahant is able to change their reactions to such experiences. These reactions would be for example reflex reactions to bad smells or tastes involving physical reactivity and mental association with smells of the past. They would not involve partiality, as an arahant does not like or dislike in the mental sense. The arahant could still perceive a bad smell as disgusting, or a beautiful flower as attractive, even though they didn't like or dislike either. 

It seems to be this freedom from partiality that allows arahants to "play" with their reactions in ways that beings with mental partialities cannot. An ordinary worldling is bound by attachments both positive and negative that force them to see attractive objects as attractive and unattractive objects as unattractive.