Why can't people change their denomination?

As my profile says, I don't belong to any denomination and I can't answer this question myself. Recently, there was a question from a Catholic woman having difficulty in her love relationship because her boyfriend from *Jehovah's Witness* can't marry her. The main problem that I suspect is that both of them are not ready to change their denomination. Here is the thing I can't understand. What is the problem with changing our denomination? Why don't people want to change their denomination? I am ready to join any denomination if required, let it be Catholic, JW, Seventh Day, Orthodox, I don't mind as long as I can read the Bible and worship Jesus. I obviously have my personal choices. I like to go to a church that uses modern instruments, good music system, good worship songs, good sermons, good Bible study programs and a good and supporting community. For now, I prefer to remain denomination-less but I think I can join any denomination and adhere to their doctrines and ordinances, if their is no other choice available. Why are people **reluctant** to change their denomination? What is the reason why some people **cannot** change their denomination? What are the major **hindrances** in changing the denomination? What kind of **challenges** are faced after changing the denomination?