A large factor in this universal acceptance is that the main character, Hamlet, around whom the entire play revolves, is realist and universal' himself. In this Hamlet is merely a reflection of aspects found in all men, he is a symbol for how any man would act given the situation. If he reacts the way you would react, that makes him a very easy to relate to and sympathetic character.
This does not mean that Hamlet reflects the common man and his action, or Rosencrantz and Guildenstern would be more probable universal men.' Hamlet reflects what the common man wishes and feels he could do if he were given the chance. Hamlet is 'superhuman' in this sense. He is able to find the strength to act though his tragic situation with out giving in to easier ways and temptations along the way. Rosencrantz and Guildenstern are more common man than universal, for though they have loyalty to Hamlet as they have been his friends for many years, they still have their own ambition.
(Gertrude) "Your visitation may receive such thanks
As fits a king's remembrance
(Rosencrantz) by the sovereign power you have of us,
(Guildenstern) Heaven make our presence and our practices Pleasant and helpful to him! [Hamlet]" (Act1, Scene2)
They make a choice, and like Judas, they make the wrong' one. They do not stand strong and faithful to Hamlet, but act on King Claudius's behalf, in hope of recognition. This is a common' man' action, to take the favorable route on the behalf of personal interest. Hamlet's main appeal is that he is trapped into a cycle, but he takes the noble and faithful action to affront the situation, leaving no doubt to the audience that he is in the right.
Though Hamlet is in a sense 'superhuman,' he is still human and easy to relate to for he does have flaws. He is not the shining hero riding in on a white horse to save the day, he is the youth who must figure out what to do before he can even act in minor ways. The problems he faces are not simple dragons', blatant evils for him to attack and get the crowds cheers. Hamlet must fight the snake,' the evil that lays hidden, and is all the more dangerous being so. Hamlet does not have the crowds on his side, he is opposing an evil no one recognizes as evil. This makes his trail all the more harder.
This complexity of evil allows Hamlets flaws to appear, for not even he recognizes the evil at first. He first recognized flaw is that of doubt. It is a realistic flaw for him to possess. Hamlet is told by a supernatural figure- that may or may not be his father- to avenge himself on Claudius, the King of Denmark. It would be too naive of Hamlet if he just took the shade at its word and used it as provocation to confront Claudius. Instead the only way available and true to his character is to reveal Claudius's guilt, with a witness to conform him. It is his subtle methods and slyness that rank him a 'superhuman' again. He takes a non-aggressive (which makes him the good and right' character) action to conform Claudius's guilt. If Hamlet is wrong than no one would know Hamlet mistake, and Claudius would not be harmed if he was innocent. Instead Hamlet proves Claudius guilt, without making Claudius too suspicious that he has found Claudius out.
(Hamlet) "-The play's the thing
Wherein I'll catch the conscience of the king (Act 2, Scene2) O good Horatio, I'll take the ghost for a thousand
pound. Didst perceive
Upon the very...