We all know that bitcoin is a decentralised crypto currency and thus there is no such proper authentic regulating body over the bitcoin who could keep eye over all the bitcoin activities and thus leading unauthorised and illegal activities and those who are having the power are doing it in their own way and I think this is the only reason for such a high transaction fee due to improper regulation but there are few countries who has legalised bitcoin in their nation and their governments are taking control over all the bitcoin activities and even the transaction fee is also normal in those nations.