Waris Shah (18th century Punjabi Muslim poet) has derided Sikhs in his poetry

Waris Shah (Punjabi Muslim poet) has derided Sikhs in his poetry. Waris Shah says that in 1766-67 AD, Jats (Sikhs) became the chieftains of Punjab. Under their rule, 'Ashrafia' (noble families) were in ruins while lowly people prospered. Thieves became Chauhdris (headmen of the village), women of bad-character assumed the garbs of righteous, and groups of ill-natured people prospered many times. 

The word Waris Shah has used, is Jat but he is definitely talking about Sikhs (who were mostly Jats) here because it was them who had achieved dominance over much of Punjab in 1767. Waris Shah has also lamented the fall of Muslim Ashrafia elsewhere:

Note that Waris Shah himself was part of the Ashrafia of Punjab. He was a Sayyid. It was natural that he would resent the fall of Ashrafia and ascendance of people who he deemed lowly. Sikhs were particularly ruthless against the Sayyids, Pirs and Mullahs of Punjab.