Why should we say ‘Sikhi’ rather than ‘Sikh-ISM’?

As we can see from the writings of the Sri Guru Granth Sahib Ji and Bhai Gurdas Ji, the term ‘Sikhi’ served as the original name for the religion. However, when the Europeans entered South Asia, their scholars used the term ‘Sikh-ism.’ Why should we have to adopt a new name when we already have a perfectly good one?

Additionally, every time we use the label ‘Sikh-ism,’ we give a little bit more power to the Western scholars while surrendering a small amount of our own. It is crucial that our community fights such lingering colonial impositions and preserves traditional, Guru-given vocabulary.