Ironically that when people don't like the attitude that does not conform to their own self ideals, they now bash it as disgusting, degrading etc etc... one that is how Rudeus dealt with his depression. by using a material manifestation of his gratitude towards the person that changed him, it is exaggerated but that does not mean it's stupid but again it's all about everyone for himself here. telling people that they should only be like this or like that or it's like this does does not really understand Freedom of Expression. their emphasis is only FREE SPEECH is only FOR THEM and not FOR EVERYONE.
also it has been pointed out that the attitude of Rudeus is a pervert. him showing off his panty idea is only for himself and not for others, which also gives that this is HIS GAG. also keeping an artifact of a person you adore or idolize is COMMON to all people.