Your first interaction with a brand/product/company, you were impressed. Second, makes you like the repeated good impression. By the third time, when you wowed again, you fall in love. Over a period of time, you are completely clouded by the loyalty you have for a company/product/person. So much so that you don’t see any shortcomings and even if you do, you are vigorously defending them.
If you think being loyal is good, you are wrong. You not only support their shortcomings, but mask their outlook affecting their betterment.
Side Note: Loyalty is like the love you have for your better half. It works there, only there.