Exactly. Let them stay happy in hands of jaahil mechanic ustaads.
I've seen a guy pouring khula oil in his Khyber and he made fun of me up on advising to go for right oil, and he proudly stated "mein tou khula oil daalta hoon, company ke dubbey ka kya faida?" The engine ceased after a while.
In another instance I came across a guy at lube shop asking for gear fluid for his Honda Vezel that uses CVT HMMF fluid. The lube shop guy told him the price and that guy said "nahin mujhe regular ATF oil hee de dein". The lube shop owner tried to convince him to go for the right HMMF fluid and warned him that ATF oil will demage the CVT transmission permanently but he insisted "jab ho ga, dekha jaaye ga". He bought ATF oil to put in Vezel's CVT transmission.
Ye tou haal hai!
For more MECHANIC USTAAD stories, please read https://www.pakwheels.com/forums/t/hilarious-stupid-funny-tricks-works-by-mechanic-ustaads/1053398?u=ahmedstudio