Why is practical disbelief considered a minor disbelief, while trampling upon the Mus'haf or throwing it into filth with the intention of insult is considered an act of disbelief that expels one from the fold of Islam, even though it is also practical?

Practical minor disbelief is every sin that the Lawgiver has termed disbelief while the doer still retains the name of faith, such as the Prophet’s (peace be upon him) saying: "Do not return to disbelief after me, striking one another’s necks." As for practical disbelief that expels one from the fold of Islam, examples include prostrating to other than Allah, sacrificing to other than Allah, insulting the religion or the Messenger, mocking Allah or the Messenger, and disrespecting the Qur'an. This, according to the Ahl al-Sunnah wal-Jama'ah, is major practical disbelief.