I have dealt with locks for a long time, they are a PITA
However, I prefer to have a lock so nobody copies or messes with my work. When a locked PCM gets to my shop I will gladly start over than messing with an unknown tune.
There are amateur tooners popping everywhere, they think because they have tuning software they can tune a car. Most of them know nothing about a car let alone tuning, but they advertise and have ridiculously low prices.
When somebody gets something for free, He/She will sell it very cheap, then the price will plummet. It is a known fact

The tunerlock is the only way to force those tooners to learn how to develop their own tunes. When they are forced to spend the time and money to learn, to practice with their own cars (if they even own one), buy equipment, buy books and dvds, read a lot. Then they will become real tuners and will not want their work copied and sold cheap.

The information is out there, you just have to spend the time and money to find it, learn and apply it. If you are too lazy or don't want to spend a dime, you should not be tuning. I spend like 4 hours a day studying and reading, I have spent thousands of dollars in books and courses, many thousands more in equipment. I'm not thrilled when somebody sells copies of my work, that's why I lock all the PCMs I tune.

A locked PCM may be a headache for the car owner but how would I know, nobody has complained yet or asked for unlock.