Hacker News Reader

That's wrong. The assumption is "even great products can get copied, and than profits go to hell.".Lock-in is one of the rare strategies that work.

No one ever leaves your first mover product to go to a copy unless they have a reason to.

Isn't lower cost reason enough ? and what about new customers(and the side effects they carry for marketing and other stuff) ?

The reason can be someone else's better advertising budget.