In both case, the problem is word order and logic. "I like more the black shirt than the blue shirt. <---Wrong. why?" English word order requires that "more" comes before "than". Here, "more" and "than" come together to form the logical operator "more than" (">" in mathematics!) "The man has juice less(more) than his son. <----- Wrong why?" This isn't totally incorrect, however, the meaning is very ambiguous. In this case, the correct sentence uses "less (more)" as a Comparative Adjective describing juice. Essentially, the word order dictates whether "more" or "less" is used as a comparative adjective or as a logical operator "more than". Also, you cannot use "more" as a comparative adjective for "like" (1st sentence) because "like" is a verb, not a noun! Hope that helps, but you ask a very challenging question!

jake, 1. I like the black shirt more than the blue shirt. <-- OK I like more the black shirt than the blue shirt. <---Wrong. why? It is not really wrong; it's just unusual word order. "More" is an adverb in this sentence meaning "to a greater degree". It has the same meaning as 1, but is not the normal way to say it with the verb "to like". For example, you could say: She is more an acquaintance than a friend. = She's an acquaintance more than a friend. or I like her more as an acquaintace than as a friend. = I like her as an acquaintance more than as a friend. 2. The man has less (more) juice than his son. <---- OK Less (more) is an adjective here modifying the noun "juice". The man has less (more) juice than his son. = The amount of juice he has or drinks is less (more) than the amount of juice his son has or drinks. The man has juice less (more) than his son. <----- Wrong why? Not wrong. Less (more) can be an adverb meaning less often or for a shorter period of time, or more often or for a longer period of time. The man has juice less (more) than his son has juice. = He has juice or drinks juice less often (more often) than his son has juice or drinks juice .

In the first case you compare two different things. In the second sentence more/less is used about quantity. Please, note that this is my opinion. I am a learner like you. May be a native speaker can explain better.