Not quite true.
There not all developers.
Some are people who have simply paid out for the developers licence to have the beta ios6.
Ones in the know will have this on secondary iPhones and not their primary iPhone just in case something happens.
Problem with beta stages are the bugs and the timeframes to download the next update or you could end up with issues.
Best to stay clear and follow the advice to wait until Apple irons out these bugs via feedback from the true developers.