I won't mention basic things like non-competition clauses, honesty etc... The majority of people are usually honest - especially those senior enough to be expos

I won't mention basic things like non-competition clauses, honesty etc... The majority of people are usually honest - especially those senior enough to be exposed to this kind of secrets / overview. But past that starting a business, especially a physical product one is not a trivial thing to do. You need to be very motivated. Like with software you discover many time-consuming details as you implement. And here not everything can be automated once solved. Even established competitors do not copy as fast as one may think because of these forces. It might be dumb money but it still isn't easy money - and that's what make it even dumber : why not invest the effort in something "better" someone will say.